some whitespace cleanup (#14443)

diff --git a/dev/benchmarks/complex_layout/lib/main.dart b/dev/benchmarks/complex_layout/lib/main.dart
index 592593f..9d2e917 100644
--- a/dev/benchmarks/complex_layout/lib/main.dart
+++ b/dev/benchmarks/complex_layout/lib/main.dart
@@ -64,7 +64,7 @@
         itemCount: 200,
         itemBuilder: (BuildContext context, int index) {
           return new Padding(
-            padding:const EdgeInsets.all(5.0),
+            padding: const EdgeInsets.all(5.0),
             child: new Material(
               elevation: (index % 5 + 1).toDouble(),
               color: Colors.white,
diff --git a/dev/bots/prepare_package.dart b/dev/bots/prepare_package.dart
index 023d00d..72b73e0 100644
--- a/dev/bots/prepare_package.dart
+++ b/dev/bots/prepare_package.dart
@@ -32,7 +32,7 @@
 
 /// Creates a pre-populated Flutter archive from a git repo.
 class ArchiveCreator {
-  /// [_tempDir] is the directory to use for creating the archive.  The script
+  /// [_tempDir] is the directory to use for creating the archive. The script
   /// will place several GiB of data there, so it should have available space.
   ///
   /// The processManager argument is used to inject a mock of [ProcessManager] for
@@ -151,7 +151,7 @@
   ///
   /// May only be run on Windows (since 7Zip is not available on other platforms).
   Future<String> _unzipArchive(File archive, {Directory currentDirectory}) {
-    assert(Platform.isWindows);  // 7Zip is only available on Windows.
+    assert(Platform.isWindows); // 7Zip is only available on Windows.
     currentDirectory ??= new Directory(path.dirname(archive.absolute.path));
     final List<String> commandLine = <String>['7za', 'x', archive.absolute.path];
     return _runProcess(commandLine, workingDirectory: currentDirectory);
@@ -161,7 +161,7 @@
   ///
   /// May only be run on Windows (since 7Zip is not available on other platforms).
   Future<String> _createZipArchive(File output, Directory source) {
-    assert(Platform.isWindows);  // 7Zip is only available on Windows.
+    assert(Platform.isWindows); // 7Zip is only available on Windows.
     final List<String> commandLine = <String>[
       '7za',
       'a',
diff --git a/dev/devicelab/lib/tasks/microbenchmarks.dart b/dev/devicelab/lib/tasks/microbenchmarks.dart
index 41f0c55..2962a5c 100644
--- a/dev/devicelab/lib/tasks/microbenchmarks.dart
+++ b/dev/devicelab/lib/tasks/microbenchmarks.dart
@@ -131,7 +131,7 @@
     if (line.contains(jsonEnd)) {
       jsonStarted = false;
       processWasKilledIntentionally = true;
-      process.kill(ProcessSignal.SIGINT);  // flutter run doesn't quit automatically
+      process.kill(ProcessSignal.SIGINT); // flutter run doesn't quit automatically
       completer.complete(JSON.decode(jsonBuf.toString()));
       return;
     }
diff --git a/dev/manual_tests/lib/card_collection.dart b/dev/manual_tests/lib/card_collection.dart
index 7cb3662..b8ff1cd 100644
--- a/dev/manual_tests/lib/card_collection.dart
+++ b/dev/manual_tests/lib/card_collection.dart
@@ -295,12 +295,12 @@
     }
 
     // TODO(abarth): This icon is wrong in RTL.
-    Widget leftArrowIcon =  const Icon(Icons.arrow_back, size: 36.0);
+    Widget leftArrowIcon = const Icon(Icons.arrow_back, size: 36.0);
     if (_dismissDirection == DismissDirection.startToEnd)
       leftArrowIcon = new Opacity(opacity: 0.1, child: leftArrowIcon);
 
       // TODO(abarth): This icon is wrong in RTL.
-    Widget rightArrowIcon =  const Icon(Icons.arrow_forward, size: 36.0);
+    Widget rightArrowIcon = const Icon(Icons.arrow_forward, size: 36.0);
     if (_dismissDirection == DismissDirection.endToStart)
       rightArrowIcon = new Opacity(opacity: 0.1, child: rightArrowIcon);
 
diff --git a/dev/manual_tests/lib/material_arc.dart b/dev/manual_tests/lib/material_arc.dart
index 3e1d130..d8aa502 100644
--- a/dev/manual_tests/lib/material_arc.dart
+++ b/dev/manual_tests/lib/material_arc.dart
@@ -27,17 +27,17 @@
   final GestureDragEndCallback onEnd;
 
   @override
-  void update(DragUpdateDetails details)  {
+  void update(DragUpdateDetails details) {
     onUpdate(details);
   }
 
   @override
-  void cancel()  {
+  void cancel() {
     onCancel();
   }
 
   @override
-  void end(DragEndDetails details)  {
+  void end(DragEndDetails details) {
     onEnd(details);
   }
 }
@@ -152,7 +152,7 @@
     return new _DragHandler(_handleDragUpdate, _handleDragCancel, _handleDragEnd);
   }
 
-  void _handleDragUpdate(DragUpdateDetails details)  {
+  void _handleDragUpdate(DragUpdateDetails details) {
     switch (_dragTarget) {
       case _DragTarget.start:
         setState(() {
@@ -167,12 +167,12 @@
     }
   }
 
-  void _handleDragCancel()  {
+  void _handleDragCancel() {
     _dragTarget = null;
     widget.controller.value = 0.0;
   }
 
-  void _handleDragEnd(DragEndDetails details)  {
+  void _handleDragEnd(DragEndDetails details) {
     _dragTarget = null;
   }
 
@@ -319,7 +319,7 @@
     return new _DragHandler(_handleDragUpdate, _handleDragCancel, _handleDragEnd);
   }
 
-  void _handleDragUpdate(DragUpdateDetails details)  {
+  void _handleDragUpdate(DragUpdateDetails details) {
     switch (_dragTarget) {
       case _DragTarget.start:
         setState(() {
@@ -334,12 +334,12 @@
     }
   }
 
-  void _handleDragCancel()  {
+  void _handleDragCancel() {
     _dragTarget = null;
     widget.controller.value = 0.0;
   }
 
-  void _handleDragEnd(DragEndDetails details)  {
+  void _handleDragEnd(DragEndDetails details) {
     _dragTarget = null;
   }
 
diff --git a/dev/manual_tests/lib/raw_keyboard.dart b/dev/manual_tests/lib/raw_keyboard.dart
index 1cf154a..bacdbb4 100644
--- a/dev/manual_tests/lib/raw_keyboard.dart
+++ b/dev/manual_tests/lib/raw_keyboard.dart
@@ -43,7 +43,7 @@
   }
 
   @override
-  Widget build(BuildContext context)  {
+  Widget build(BuildContext context) {
     final TextTheme textTheme = Theme.of(context).textTheme;
     return new RawKeyboardListener(
       focusNode: _focusNode,
diff --git a/dev/tools/gen_date_localizations.dart b/dev/tools/gen_date_localizations.dart
index d48271c..ad46156 100644
--- a/dev/tools/gen_date_localizations.dart
+++ b/dev/tools/gen_date_localizations.dart
@@ -75,7 +75,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// This file has been automatically generated.  Please do not edit it manually.
+// This file has been automatically generated. Please do not edit it manually.
 // To regenerate run (omit -w to print to console instead of the file):
 // dart --enable-asserts dev/tools/gen_date_localizations.dart --overwrite
 
diff --git a/dev/tools/test/fake_process_manager.dart b/dev/tools/test/fake_process_manager.dart
index 1a5afab..7c4c456 100644
--- a/dev/tools/test/fake_process_manager.dart
+++ b/dev/tools/test/fake_process_manager.dart
@@ -27,7 +27,7 @@
   final StringReceivedCallback stdinResults;
 
   /// The list of results that will be sent back, organized by the command line
-  /// that will produce them.  Each command line has a list of returned stdout
+  /// that will produce them. Each command line has a list of returned stdout
   /// output that will be returned on each successive call.
   Map<String, List<ProcessResult>> fakeResults = <String, List<ProcessResult>>{};
 
diff --git a/dev/tools/vitool/lib/vitool.dart b/dev/tools/vitool/lib/vitool.dart
index 22bb562..b2e52d8 100644
--- a/dev/tools/vitool/lib/vitool.dart
+++ b/dev/tools/vitool/lib/vitool.dart
@@ -267,7 +267,7 @@
   final List<SvgPath> paths;
 
   @override
-  bool operator ==(Object other){
+  bool operator ==(Object other) {
     if (runtimeType != other.runtimeType)
       return false;
     final FrameData typedOther = other;
@@ -464,7 +464,7 @@
 final RegExp _transformValidator = new RegExp('^($_transformCommandAtom)*\$');
 final RegExp _transformCommand = new RegExp(_transformCommandAtom);
 
-Matrix3 _parseSvgTransform(String transform){
+Matrix3 _parseSvgTransform(String transform) {
   if (!_transformValidator.hasMatch(transform))
     throw new Exception('illegal or unsupported transform: $transform');
   final Iterable<Match> matches =_transformCommand.allMatches(transform).toList().reversed;