Reorganise flutter driver implementation sources (#13163)

This patch reorganises flutter_driver's lib/src directory into three
subdirectories:

* driver: sources transitively imported/exported by flutter_driver.dart,
  which defines the API used by driver tests executed on the host machine.

* extension: sources transitively imported/exported by
  driver_extension.dart, which defines the API used to instrument a
  Flutter app running on the target device for use with a driver test.

* common: sources common to both driver and extension code.

This makes rolling Flutter into repositories that use Bazel (or
Bazel-like build systems) significantly more robust, due to the simpler
glob patterns involved.

packages/flutter_driver/lib/driver_extension.dart

@@ -24,4 +24,4 @@
 ///     }
 library flutter_driver_extension;
 
-export 'src/extension.dart' show enableFlutterDriverExtension, DataHandler;
+export 'src/extension/extension.dart' show enableFlutterDriverExtension, DataHandler;

packages/flutter_driver/lib/flutter_driver.dart

@@ -11,32 +11,32 @@
 /// Protractor (Angular), Espresso (Android) or Earl Gray (iOS).
 library flutter_driver;
 
-export 'src/common.dart' show
+export 'src/common/error.dart' show
+  DriverError,
+  LogLevel,
+  LogRecord,
+  flutterDriverLog;
+export 'src/common/find.dart' show
+  SerializableFinder;
+export 'src/common/health.dart' show
+  Health,
+  HealthStatus;
+export 'src/common/message.dart' show
+  Command,
+  Result;
+export 'src/common/render_tree.dart' show
+  RenderTree;
+export 'src/driver/common.dart' show
   testOutputsDirectory;
-export 'src/driver.dart' show
+export 'src/driver/driver.dart' show
   find,
   CommonFinders,
   EvaluatorFunction,
   FlutterDriver,
   TimelineStream;
-export 'src/error.dart' show
+export 'src/driver/timeline.dart' show
-  DriverError,
-  LogLevel,
-  LogRecord,
-  flutterDriverLog;
-export 'src/find.dart' show
-  SerializableFinder;
-export 'src/health.dart' show
-  Health,
-  HealthStatus;
-export 'src/message.dart' show
-  Command,
-  Result;
-export 'src/render_tree.dart' show
-  RenderTree;
-export 'src/timeline.dart' show
   Timeline,
   TimelineEvent;
-export 'src/timeline_summary.dart' show
+export 'src/driver/timeline_summary.dart' show
   TimelineSummary,
   kBuildBudget;

packages/flutter_driver/lib/src/driver/driver.dart

@@ -14,16 +14,16 @@ import 'package:path/path.dart' as p;
 import 'package:vm_service_client/vm_service_client.dart';
 import 'package:web_socket_channel/io.dart';
 
+import '../common/error.dart';
+import '../common/find.dart';
+import '../common/frame_sync.dart';
+import '../common/gesture.dart';
+import '../common/health.dart';
+import '../common/message.dart';
+import '../common/render_tree.dart';
+import '../common/request_data.dart';
+import '../common/semantics.dart';
 import 'common.dart';
-import 'error.dart';
-import 'find.dart';
-import 'frame_sync.dart';
-import 'gesture.dart';
-import 'health.dart';
-import 'message.dart';
-import 'render_tree.dart';
-import 'request_data.dart';
-import 'semantics.dart';
 import 'timeline.dart';
 
 /// Timeline stream identifier.

packages/flutter_driver/lib/src/extension/extension.dart

@@ -15,15 +15,15 @@ import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import 'error.dart';
+import '../common/error.dart';
-import 'find.dart';
+import '../common/find.dart';
-import 'frame_sync.dart';
+import '../common/frame_sync.dart';
-import 'gesture.dart';
+import '../common/gesture.dart';
-import 'health.dart';
+import '../common/health.dart';
-import 'message.dart';
+import '../common/message.dart';
-import 'render_tree.dart';
+import '../common/render_tree.dart';
-import 'request_data.dart';
+import '../common/request_data.dart';
-import 'semantics.dart';
+import '../common/semantics.dart';
 
 const String _extensionMethodName = 'driver';
 const String _extensionMethod = 'ext.flutter.$_extensionMethodName';

packages/flutter_driver/test/flutter_driver_test.dart

@@ -4,10 +4,10 @@
 
 import 'dart:async';
 
-import 'package:flutter_driver/src/driver.dart';
+import 'package:flutter_driver/src/common/error.dart';
-import 'package:flutter_driver/src/error.dart';
+import 'package:flutter_driver/src/common/health.dart';
-import 'package:flutter_driver/src/health.dart';
+import 'package:flutter_driver/src/driver/driver.dart';
-import 'package:flutter_driver/src/timeline.dart';
+import 'package:flutter_driver/src/driver/timeline.dart';
 import 'package:json_rpc_2/json_rpc_2.dart' as rpc;
 import 'package:mockito/mockito.dart';
 import 'package:test/test.dart';

packages/flutter_driver/test/src/extension_test.dart

@@ -3,9 +3,9 @@
 // found in the LICENSE file.
 
 import 'package:flutter/scheduler.dart';
-import 'package:flutter_driver/src/extension.dart';
+import 'package:flutter_driver/src/common/find.dart';
-import 'package:flutter_driver/src/find.dart';
+import 'package:flutter_driver/src/common/request_data.dart';
-import 'package:flutter_driver/src/request_data.dart';
+import 'package:flutter_driver/src/extension/extension.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {

packages/flutter_driver/test/src/timeline_summary_test.dart

@@ -5,10 +5,10 @@
 import 'dart:convert' show JSON;
 
 import 'package:file/file.dart';
+import 'package:flutter_driver/flutter_driver.dart';
+import 'package:flutter_driver/src/driver/common.dart';
 import 'package:path/path.dart' as path;
 import 'package:test/test.dart';
-import 'package:flutter_driver/src/common.dart';
-import 'package:flutter_driver/flutter_driver.dart';
 
 void main() {
   group('TimelineSummary', () {

packages/flutter_driver/test/src/timeline_test.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:test/test.dart';
-import 'package:flutter_driver/src/timeline.dart';
+import 'package:flutter_driver/src/driver/timeline.dart';
 
 void main() {
   group('Timeline', () {