gamepad dispatcher: pass in execution context

Pass EC in instead of the task runner. Puts the task type in the
dispatcher class instead of the calling class. Dropped std::move:
  error: moving a temporary object prevents copy elision

Also paves the way for some new objects which will need the
execution context.

Change-Id: Id0608ccf129443532091e7bdfe0afccb146172ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2152134Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Commit-Queue: Johann Koenig <johannkoenig@google.com>
Cr-Commit-Position: refs/heads/master@{#762725}

third_party/blink/renderer/modules/gamepad/gamepad_dispatcher.cc

@@ -40,9 +40,10 @@ void GamepadDispatcher::ResetVibrationActuator(
                                                           std::move(callback));
 }
 
-GamepadDispatcher::GamepadDispatcher(
-    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
-    : task_runner_(std::move(task_runner)) {}
+GamepadDispatcher::GamepadDispatcher(ExecutionContext* context)
+    :  // See https://bit.ly/2S0zRAS for task types.
+      task_runner_(context ? context->GetTaskRunner(TaskType::kMiscPlatformAPI)
+                           : nullptr) {}
 
 GamepadDispatcher::~GamepadDispatcher() = default;
 

third_party/blink/renderer/modules/gamepad/gamepad_dispatcher.h

@@ -10,6 +10,7 @@
 #include "base/memory/scoped_refptr.h"
 #include "device/gamepad/public/mojom/gamepad.mojom-blink.h"
 #include "mojo/public/cpp/bindings/remote.h"
+#include "third_party/blink/renderer/core/execution_context/execution_context.h"
 #include "third_party/blink/renderer/core/frame/platform_event_dispatcher.h"
 #include "third_party/blink/renderer/modules/gamepad/gamepad_listener.h"
 
@@ -28,8 +29,7 @@ class GamepadDispatcher final : public GarbageCollected<GamepadDispatcher>,
   USING_GARBAGE_COLLECTED_MIXIN(GamepadDispatcher);
 
  public:
-  explicit GamepadDispatcher(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  explicit GamepadDispatcher(ExecutionContext* context);
   ~GamepadDispatcher() override;
 
   void SampleGamepads(device::Gamepads&);

third_party/blink/renderer/modules/gamepad/gamepad_haptic_actuator.cc

@@ -70,9 +70,7 @@ GamepadHapticActuator::GamepadHapticActuator(
     device::GamepadHapticActuatorType type)
     : ExecutionContextClient(context),
       pad_index_(pad_index),
-      // See https://bit.ly/2S0zRAS for task types
-      gamepad_dispatcher_(MakeGarbageCollected<GamepadDispatcher>(
-          context->GetTaskRunner(TaskType::kMiscPlatformAPI))) {
+      gamepad_dispatcher_(MakeGarbageCollected<GamepadDispatcher>(context)) {
   SetType(type);
 }
 

third_party/blink/renderer/modules/gamepad/navigator_gamepad.cc

@@ -195,11 +195,8 @@ NavigatorGamepad::NavigatorGamepad(Navigator& navigator)
       ExecutionContextClient(navigator.DomWindow()),
       PlatformEventController(
           navigator.GetFrame() ? navigator.GetFrame()->GetDocument() : nullptr),
-      // See https://bit.ly/2S0zRAS for task types
-      gamepad_dispatcher_(MakeGarbageCollected<GamepadDispatcher>(
-          navigator.GetFrame() ? navigator.GetFrame()->GetTaskRunner(
-                                     blink::TaskType::kMiscPlatformAPI)
-                               : nullptr)) {
+      gamepad_dispatcher_(
+          MakeGarbageCollected<GamepadDispatcher>(navigator.DomWindow())) {
   if (navigator.DomWindow())
     navigator.DomWindow()->RegisterEventListenerObserver(this);