Decouple GamepadSharedMemory into Blink.

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index 8295ac864c70d110b334e1333f509a42e3db4b39..fa66d2c61758911ffe215b71e9fd04fa28cc7a41 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -54,7 +54,6 @@
 #include "content/renderer/dom_storage/local_storage_cached_areas.h"
 #include "content/renderer/dom_storage/local_storage_namespace.h"
 #include "content/renderer/dom_storage/webstoragenamespace_impl.h"
-#include "content/renderer/gamepad_shared_memory_reader.h"
 #include "content/renderer/media/audio_decoder.h"
 #include "content/renderer/media/audio_device_factory.h"
 #include "content/renderer/media/canvas_capture_handler.h"
@@ -91,7 +90,6 @@
 #include "third_party/WebKit/public/platform/WebBlobRegistry.h"
 #include "third_party/WebKit/public/platform/WebDeviceLightListener.h"
 #include "third_party/WebKit/public/platform/WebFileInfo.h"
-#include "third_party/WebKit/public/platform/WebGamepads.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamCenter.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamCenterClient.h"
 #include "third_party/WebKit/public/platform/WebPluginListBuilder.h"
@@ -148,8 +146,6 @@ using blink::WebCanvasCaptureHandler;
 using blink::WebDatabaseObserver;
 using blink::WebFileInfo;
 using blink::WebFileSystem;
-using blink::WebGamepad;
-using blink::WebGamepads;
 using blink::WebIDBFactory;
 using blink::WebImageCaptureFrameGrabber;
 using blink::WebMIDIAccessor;
@@ -810,16 +806,6 @@ WebBlobRegistry* RendererBlinkPlatformImpl::getBlobRegistry() {
 
 //------------------------------------------------------------------------------
 
-void RendererBlinkPlatformImpl::sampleGamepads(WebGamepads& gamepads) {

[ke.he, 2016/12/15 14:35:56]

Before decoupling, sampleGamepads() is defined in Platform.h and is implemented
here which belongs to content layer. It means "blink ask outside to implement
sampleGamepads()".

After decoupling, sampleGamepads() can be implemented totally inside blink. It
becomes into "blink expose a interface to outside." The interface exposing is
necessary because there are calls from pepper:
https://cs.chromium.org/chromium/src/content/renderer/pepper/pepper_plugin_in...

I heard the change of blink interface is quite serious, I'm not sure if the such
kind of changes is ok.

-  PlatformEventObserverBase* observer =
-      platform_event_observers_.Lookup(blink::WebPlatformEventTypeGamepad);
-  if (!observer)
-    return;
-  static_cast<RendererGamepadProvider*>(observer)->SampleGamepads(gamepads);
-}
-
-//------------------------------------------------------------------------------
-
 WebMediaRecorderHandler*
 RendererBlinkPlatformImpl::createMediaRecorderHandler() {
 #if BUILDFLAG(ENABLE_WEBRTC)
@@ -1180,8 +1166,6 @@ RendererBlinkPlatformImpl::CreatePlatformEventObserverFromType(
       return base::MakeUnique<DeviceOrientationAbsoluteEventPump>(thread);
     case blink::WebPlatformEventTypeDeviceLight:
       return base::MakeUnique<DeviceLightEventPump>(thread);
-    case blink::WebPlatformEventTypeGamepad:
-      return base::MakeUnique<GamepadSharedMemoryReader>(thread);
     case blink::WebPlatformEventTypeScreenOrientation:
       return base::MakeUnique<ScreenOrientationObserver>();
     default: