diff --git a/packages/camera/CHANGELOG.md b/packages/camera/CHANGELOG.md
index 9ed7a78f1bb1..45a2235043e6 100644
--- a/packages/camera/CHANGELOG.md
+++ b/packages/camera/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.5.4+2
+
+* Fix Android NullPointerException on devices with only front-facing camera.
+
 ## 0.5.4+1
 
 * Fix Android pause and resume video crash when executing in APIs below 24.
diff --git a/packages/camera/android/src/main/java/io/flutter/plugins/camera/CameraUtils.java b/packages/camera/android/src/main/java/io/flutter/plugins/camera/CameraUtils.java
index e4613fb237c1..a7bb3b7d4914 100644
--- a/packages/camera/android/src/main/java/io/flutter/plugins/camera/CameraUtils.java
+++ b/packages/camera/android/src/main/java/io/flutter/plugins/camera/CameraUtils.java
@@ -77,32 +77,31 @@ static CamcorderProfile getBestAvailableCamcorderProfileForResolutionPreset(
         // All of these cases deliberately fall through to get the best available profile.
       case max:
         if (CamcorderProfile.hasProfile(cameraId, CamcorderProfile.QUALITY_HIGH)) {
-          return CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
+          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_HIGH);
         }
       case ultraHigh:
         if (CamcorderProfile.hasProfile(cameraId, CamcorderProfile.QUALITY_2160P)) {
-          return CamcorderProfile.get(CamcorderProfile.QUALITY_2160P);
+          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_2160P);
         }
       case veryHigh:
         if (CamcorderProfile.hasProfile(cameraId, CamcorderProfile.QUALITY_1080P)) {
-          return CamcorderProfile.get(CamcorderProfile.QUALITY_1080P);
+          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_1080P);
         }
       case high:
         if (CamcorderProfile.hasProfile(cameraId, CamcorderProfile.QUALITY_720P)) {
-          return CamcorderProfile.get(CamcorderProfile.QUALITY_720P);
+          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_720P);
         }
       case medium:
         if (CamcorderProfile.hasProfile(cameraId, CamcorderProfile.QUALITY_480P)) {
-          return CamcorderProfile.get(CamcorderProfile.QUALITY_480P);
+          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_480P);
         }
       case low:
         if (CamcorderProfile.hasProfile(cameraId, CamcorderProfile.QUALITY_QVGA)) {
-          return CamcorderProfile.get(CamcorderProfile.QUALITY_QVGA);
+          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_QVGA);
         }
       default:
-        if (CamcorderProfile.hasProfile(
-            Integer.parseInt(cameraName), CamcorderProfile.QUALITY_LOW)) {
-          return CamcorderProfile.get(CamcorderProfile.QUALITY_LOW);
+        if (CamcorderProfile.hasProfile(cameraId, CamcorderProfile.QUALITY_LOW)) {
+          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_LOW);
         } else {
           throw new IllegalArgumentException(
               "No capture session available for current capture session.");
diff --git a/packages/camera/pubspec.yaml b/packages/camera/pubspec.yaml
index c9e715225d59..e7c8632b042f 100644
--- a/packages/camera/pubspec.yaml
+++ b/packages/camera/pubspec.yaml
@@ -2,7 +2,7 @@ name: camera
 description: A Flutter plugin for getting information about and controlling the
   camera on Android and iOS. Supports previewing the camera feed, capturing images, capturing video,
   and streaming image buffers to dart.
-version: 0.5.4+1
+version: 0.5.4+2
 
 authors:
   - Flutter Team <flutter-dev@googlegroups.com>
diff --git a/packages/google_maps_flutter/CHANGELOG.md b/packages/google_maps_flutter/CHANGELOG.md
index addc8831efe3..e6f2ff00d02f 100644
--- a/packages/google_maps_flutter/CHANGELOG.md
+++ b/packages/google_maps_flutter/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.5.21+2
+
+* Fix more `prefer_const_constructors` analyzer warnings in example app.
+
 ## 0.5.21+1
 
 * Fix `prefer_const_constructors` analyzer warnings in example app.
diff --git a/packages/google_maps_flutter/example/lib/padding.dart b/packages/google_maps_flutter/example/lib/padding.dart
index 599f8a564b6e..6c1fe38dbf3a 100644
--- a/packages/google_maps_flutter/example/lib/padding.dart
+++ b/packages/google_maps_flutter/example/lib/padding.dart
@@ -98,7 +98,7 @@ class MarkerIconsBodyState extends State<MarkerIconsBody> {
               ),
             ),
           ),
-          Spacer(),
+          const Spacer(),
           Flexible(
             flex: 2,
             child: TextField(
@@ -110,7 +110,7 @@ class MarkerIconsBodyState extends State<MarkerIconsBody> {
               ),
             ),
           ),
-          Spacer(),
+          const Spacer(),
           Flexible(
             flex: 2,
             child: TextField(
@@ -122,7 +122,7 @@ class MarkerIconsBodyState extends State<MarkerIconsBody> {
               ),
             ),
           ),
-          Spacer(),
+          const Spacer(),
           Flexible(
             flex: 2,
             child: TextField(
diff --git a/packages/google_maps_flutter/pubspec.yaml b/packages/google_maps_flutter/pubspec.yaml
index a72cb71fdd78..7de1fd6bca7d 100644
--- a/packages/google_maps_flutter/pubspec.yaml
+++ b/packages/google_maps_flutter/pubspec.yaml
@@ -2,7 +2,7 @@ name: google_maps_flutter
 description: A Flutter plugin for integrating Google Maps in iOS and Android applications.
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/google_maps_flutter
-version: 0.5.21+1
+version: 0.5.21+2
 
 dependencies:
   flutter:
diff --git a/packages/google_sign_in/CHANGELOG.md b/packages/google_sign_in/CHANGELOG.md
index 92bf3230e06c..188167e53cae 100644
--- a/packages/google_sign_in/CHANGELOG.md
+++ b/packages/google_sign_in/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 4.0.8
+
+* Get rid of `MethodCompleter` and serialize async actions using chained futures.
+  This prevents a bug when sign in methods are being used in error handling zones.
+
 ## 4.0.7
 
 * Switch from using `api` to `implementation` for dependency on `play-services-auth`,
diff --git a/packages/google_sign_in/lib/google_sign_in.dart b/packages/google_sign_in/lib/google_sign_in.dart
old mode 100755
new mode 100644
index ca6e6bbaf705..f1e1db21801e
--- a/packages/google_sign_in/lib/google_sign_in.dart
+++ b/packages/google_sign_in/lib/google_sign_in.dart
@@ -230,50 +230,57 @@ class GoogleSignIn {
   }
 
   Future<void> _ensureInitialized() {
-    if (_initialization == null) {
-      _initialization = channel.invokeMethod<void>('init', <String, dynamic>{
-        'signInOption': (signInOption ?? SignInOption.standard).toString(),
-        'scopes': scopes ?? <String>[],
-        'hostedDomain': hostedDomain,
-      })
-        ..catchError((dynamic _) {
-          // Invalidate initialization if it errored out.
-          _initialization = null;
-        });
-    }
-    return _initialization;
+    return _initialization ??=
+        channel.invokeMethod<void>('init', <String, dynamic>{
+      'signInOption': (signInOption ?? SignInOption.standard).toString(),
+      'scopes': scopes ?? <String>[],
+      'hostedDomain': hostedDomain,
+    })
+          ..catchError((dynamic _) {
+            // Invalidate initialization if it errored out.
+            _initialization = null;
+          });
   }
 
-  /// Keeps track of the most recently scheduled method call.
-  _MethodCompleter _lastMethodCompleter;
+  /// The most recently scheduled method call.
+  Future<void> _lastMethodCall;
+
+  /// Returns a [Future] that completes with a success after [future], whether
+  /// it completed with a value or an error.
+  static Future<void> _waitFor(Future<void> future) {
+    final Completer<void> completer = Completer<void>();
+    future.whenComplete(completer.complete).catchError((dynamic _) {
+      // Ignore if previous call completed with an error.
+    });
+    return completer.future;
+  }
 
   /// Adds call to [method] in a queue for execution.
   ///
   /// At most one in flight call is allowed to prevent concurrent (out of order)
   /// updates to [currentUser] and [onCurrentUserChanged].
-  Future<GoogleSignInAccount> _addMethodCall(String method) {
-    if (_lastMethodCompleter == null) {
-      _lastMethodCompleter = _MethodCompleter(method)
-        ..complete(_callMethod(method));
-      return _lastMethodCompleter.future;
+  Future<GoogleSignInAccount> _addMethodCall(String method) async {
+    Future<GoogleSignInAccount> response;
+    if (_lastMethodCall == null) {
+      response = _callMethod(method);
+    } else {
+      response = _lastMethodCall.then((_) {
+        // If after the last completed call `currentUser` is not `null` and requested
+        // method is a sign in method, re-use the same authenticated user
+        // instead of making extra call to the native side.
+        const List<String> kSignInMethods = <String>[
+          'signIn',
+          'signInSilently'
+        ];
+        if (kSignInMethods.contains(method) && _currentUser != null) {
+          return _currentUser;
+        } else {
+          return _callMethod(method);
+        }
+      });
     }
-
-    final _MethodCompleter completer = _MethodCompleter(method);
-    _lastMethodCompleter.future.whenComplete(() {
-      // If after the last completed call currentUser is not null and requested
-      // method is a sign in method, re-use the same authenticated user
-      // instead of making extra call to the native side.
-      const List<String> kSignInMethods = <String>['signIn', 'signInSilently'];
-      if (kSignInMethods.contains(method) && _currentUser != null) {
-        completer.complete(_currentUser);
-      } else {
-        completer.complete(_callMethod(method));
-      }
-    }).catchError((dynamic _) {
-      // Ignore if previous call completed with an error.
-    });
-    _lastMethodCompleter = completer;
-    return _lastMethodCompleter.future;
+    _lastMethodCall = _waitFor(response);
+    return response;
   }
 
   /// The currently signed in account, or null if the user is signed out.
@@ -296,12 +303,17 @@ class GoogleSignIn {
   /// returned Future completes with [PlatformException] whose `code` can be
   /// either [kSignInRequiredError] (when there is no authenticated user) or
   /// [kSignInFailedError] (when an unknown error occurred).
-  Future<GoogleSignInAccount> signInSilently({bool suppressErrors = true}) {
-    final Future<GoogleSignInAccount> result = _addMethodCall('signInSilently');
-    if (suppressErrors) {
-      return result.catchError((dynamic _) => null);
+  Future<GoogleSignInAccount> signInSilently(
+      {bool suppressErrors = true}) async {
+    try {
+      return await _addMethodCall('signInSilently');
+    } catch (_) {
+      if (suppressErrors) {
+        return null;
+      } else {
+        rethrow;
+      }
     }
-    return result;
   }
 
   /// Returns a future that resolves to whether a user is currently signed in.
@@ -334,26 +346,3 @@ class GoogleSignIn {
   /// authentication.
   Future<GoogleSignInAccount> disconnect() => _addMethodCall('disconnect');
 }
-
-class _MethodCompleter {
-  _MethodCompleter(this.method);
-
-  final String method;
-  final Completer<GoogleSignInAccount> _completer =
-      Completer<GoogleSignInAccount>();
-
-  Future<void> complete(FutureOr<GoogleSignInAccount> value) async {
-    if (value is Future<GoogleSignInAccount>) {
-      try {
-        _completer.complete(await value);
-      } catch (e, stacktrace) {
-        _completer.completeError(e, stacktrace);
-      }
-    } else {
-      _completer.complete(value);
-    }
-  }
-
-  bool get isCompleted => _completer.isCompleted;
-  Future<GoogleSignInAccount> get future => _completer.future;
-}
diff --git a/packages/google_sign_in/pubspec.yaml b/packages/google_sign_in/pubspec.yaml
old mode 100755
new mode 100644
index 6ed758895bf7..246a6389e39c
--- a/packages/google_sign_in/pubspec.yaml
+++ b/packages/google_sign_in/pubspec.yaml
@@ -3,7 +3,7 @@ description: Flutter plugin for Google Sign-In, a secure authentication system
   for signing in with a Google account on Android and iOS.
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/google_sign_in
-version: 4.0.7
+version: 4.0.8
 
 flutter:
   plugin:
diff --git a/packages/google_sign_in/test/google_sign_in_test.dart b/packages/google_sign_in/test/google_sign_in_test.dart
index dab480a4cce4..108edf9c892b 100755
--- a/packages/google_sign_in/test/google_sign_in_test.dart
+++ b/packages/google_sign_in/test/google_sign_in_test.dart
@@ -45,7 +45,11 @@ void main() {
       responses = Map<String, dynamic>.from(kDefaultResponses);
       channel.setMockMethodCallHandler((MethodCall methodCall) {
         log.add(methodCall);
-        return Future<dynamic>.value(responses[methodCall.method]);
+        final dynamic response = responses[methodCall.method];
+        if (response != null && response is Exception) {
+          return Future<dynamic>.error('$response');
+        }
+        return Future<dynamic>.value(response);
       });
       googleSignIn = GoogleSignIn();
       log.clear();
@@ -142,6 +146,27 @@ void main() {
       ]);
     });
 
+    test('signIn works even if a previous call throws error in other zone',
+        () async {
+      responses['signInSilently'] = Exception('Not a user');
+      await runZoned(() async {
+        expect(await googleSignIn.signInSilently(), isNull);
+      }, onError: (dynamic e, dynamic st) {});
+      expect(await googleSignIn.signIn(), isNotNull);
+      expect(
+        log,
+        <Matcher>[
+          isMethodCall('init', arguments: <String, dynamic>{
+            'signInOption': 'SignInOption.standard',
+            'scopes': <String>[],
+            'hostedDomain': null,
+          }),
+          isMethodCall('signInSilently', arguments: null),
+          isMethodCall('signIn', arguments: null),
+        ],
+      );
+    });
+
     test('concurrent calls of the same method trigger sign in once', () async {
       final List<Future<GoogleSignInAccount>> futures =
           <Future<GoogleSignInAccount>>[
@@ -170,7 +195,7 @@ void main() {
     });
 
     test('can sign in after previously failed attempt', () async {
-      responses['signInSilently'] = <String, dynamic>{'error': 'Not a user'};
+      responses['signInSilently'] = Exception('Not a user');
       expect(await googleSignIn.signInSilently(), isNull);
       expect(await googleSignIn.signIn(), isNotNull);
       expect(
diff --git a/packages/url_launcher/CHANGELOG.md b/packages/url_launcher/CHANGELOG.md
index db2ace15b1e9..0ffbf290a5f7 100644
--- a/packages/url_launcher/CHANGELOG.md
+++ b/packages/url_launcher/CHANGELOG.md
@@ -1,3 +1,8 @@
+
+## 5.1.3
+
+* Always launch url from the top most UIViewController in iOS.
+
 ## 5.1.2
 
 * Update AGP and gradle.
diff --git a/packages/url_launcher/ios/Classes/UrlLauncherPlugin.m b/packages/url_launcher/ios/Classes/UrlLauncherPlugin.m
index 56681dcd1ee3..b21829867a7e 100644
--- a/packages/url_launcher/ios/Classes/UrlLauncherPlugin.m
+++ b/packages/url_launcher/ios/Classes/UrlLauncherPlugin.m
@@ -61,33 +61,16 @@ @interface FLTUrlLauncherPlugin ()
 
 @end
 
-@interface FLTUrlLauncherPlugin ()
-
-@property(strong, nonatomic) UIViewController *viewController;
-
-@end
-
 @implementation FLTUrlLauncherPlugin
 
 + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
   FlutterMethodChannel *channel =
       [FlutterMethodChannel methodChannelWithName:@"plugins.flutter.io/url_launcher"
                                   binaryMessenger:registrar.messenger];
-  UIViewController *viewController =
-      [UIApplication sharedApplication].delegate.window.rootViewController;
-  FLTUrlLauncherPlugin *plugin =
-      [[FLTUrlLauncherPlugin alloc] initWithViewController:viewController];
+  FLTUrlLauncherPlugin *plugin = [[FLTUrlLauncherPlugin alloc] init];
   [registrar addMethodCallDelegate:plugin channel:channel];
 }
 
-- (instancetype)initWithViewController:(UIViewController *)viewController {
-  self = [super init];
-  if (self) {
-    self.viewController = viewController;
-  }
-  return self;
-}
-
 - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
   NSString *url = call.arguments[@"url"];
   if ([@"canLaunch" isEqualToString:call.method]) {
@@ -153,9 +136,9 @@ - (void)launchURLInVC:(NSString *)urlString result:(FlutterResult)result API_AVA
   self.currentSession.didFinish = ^(void) {
     weakSelf.currentSession = nil;
   };
-  [self.viewController presentViewController:self.currentSession.safari
-                                    animated:YES
-                                  completion:nil];
+  [self.topViewController presentViewController:self.currentSession.safari
+                                       animated:YES
+                                     completion:nil];
 }
 
 - (void)closeWebViewWithResult:(FlutterResult)result API_AVAILABLE(ios(9.0)) {
@@ -165,4 +148,36 @@ - (void)closeWebViewWithResult:(FlutterResult)result API_AVAILABLE(ios(9.0)) {
   result(nil);
 }
 
+- (UIViewController *)topViewController {
+  return [self topViewControllerFromViewController:[UIApplication sharedApplication]
+                                                       .keyWindow.rootViewController];
+}
+
+/**
+ * This method recursively iterate through the view hierarchy
+ * to return the top most view controller.
+ *
+ * It supports the following scenarios:
+ *
+ * - The view controller is presenting another view.
+ * - The view controller is a UINavigationController.
+ * - The view controller is a UITabBarController.
+ *
+ * @return The top most view controller.
+ */
+- (UIViewController *)topViewControllerFromViewController:(UIViewController *)viewController {
+  if ([viewController isKindOfClass:[UINavigationController class]]) {
+    UINavigationController *navigationController = (UINavigationController *)viewController;
+    return [self
+        topViewControllerFromViewController:[navigationController.viewControllers lastObject]];
+  }
+  if ([viewController isKindOfClass:[UITabBarController class]]) {
+    UITabBarController *tabController = (UITabBarController *)viewController;
+    return [self topViewControllerFromViewController:tabController.selectedViewController];
+  }
+  if (viewController.presentedViewController) {
+    return [self topViewControllerFromViewController:viewController.presentedViewController];
+  }
+  return viewController;
+}
 @end
diff --git a/packages/url_launcher/pubspec.yaml b/packages/url_launcher/pubspec.yaml
index f7b77db58818..34343639e9f2 100644
--- a/packages/url_launcher/pubspec.yaml
+++ b/packages/url_launcher/pubspec.yaml
@@ -3,7 +3,7 @@ description: Flutter plugin for launching a URL on Android and iOS. Supports
   web, phone, SMS, and email schemes.
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/url_launcher
-version: 5.1.2
+version: 5.1.3
 
 flutter:
   plugin:
diff --git a/packages/webview_flutter/CHANGELOG.md b/packages/webview_flutter/CHANGELOG.md
index 4419c2f2f03a..98e312afd3a3 100644
--- a/packages/webview_flutter/CHANGELOG.md
+++ b/packages/webview_flutter/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.3.14+1
+
+* Allow underscores anywhere for Javascript Channel name.
+
 ## 0.3.14
 
 * Added a getTitle getter to WebViewController.
diff --git a/packages/webview_flutter/lib/webview_flutter.dart b/packages/webview_flutter/lib/webview_flutter.dart
index dec62b700122..cd5ca46701d7 100644
--- a/packages/webview_flutter/lib/webview_flutter.dart
+++ b/packages/webview_flutter/lib/webview_flutter.dart
@@ -91,7 +91,7 @@ enum AutoMediaPlaybackPolicy {
   always_allow,
 }
 
-final RegExp _validChannelNames = RegExp('^[a-zA-Z_][a-zA-Z0-9]*\$');
+final RegExp _validChannelNames = RegExp('^[a-zA-Z_][a-zA-Z0-9_]*\$');
 
 /// A named channel for receiving messaged from JavaScript code running inside a web view.
 class JavascriptChannel {
diff --git a/packages/webview_flutter/pubspec.yaml b/packages/webview_flutter/pubspec.yaml
index 69f45118de0a..e5f39f14da87 100644
--- a/packages/webview_flutter/pubspec.yaml
+++ b/packages/webview_flutter/pubspec.yaml
@@ -1,6 +1,6 @@
 name: webview_flutter
 description: A Flutter plugin that provides a WebView widget on Android and iOS.
-version: 0.3.14
+version: 0.3.14+1
 author: Flutter Team <flutter-dev@googlegroups.com>
 homepage: https://github.com/flutter/plugins/tree/master/packages/webview_flutter
 
diff --git a/packages/webview_flutter/test/webview_flutter_test.dart b/packages/webview_flutter/test/webview_flutter_test.dart
index d3f289018073..5184ddd13de3 100644
--- a/packages/webview_flutter/test/webview_flutter_test.dart
+++ b/packages/webview_flutter/test/webview_flutter_test.dart
@@ -454,6 +454,7 @@ void main() {
     final JavascriptMessageHandler noOp = (JavascriptMessage msg) {};
     JavascriptChannel(name: 'Tts1', onMessageReceived: noOp);
     JavascriptChannel(name: '_Alarm', onMessageReceived: noOp);
+    JavascriptChannel(name: 'foo_bar_', onMessageReceived: noOp);
 
     VoidCallback createChannel(String name) {
       return () {