cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/tiles/gpu_image_decode_controller.cc

Index: cc/tiles/gpu_image_decode_controller.cc
diff --git a/cc/tiles/gpu_image_decode_controller.cc b/cc/tiles/gpu_image_decode_controller.cc
index b7dbd55f116d1900fca133a64d710abf086376a3..69a3327e385edfd4b7b068563bb4316d578efeb7 100644
--- a/cc/tiles/gpu_image_decode_controller.cc
+++ b/cc/tiles/gpu_image_decode_controller.cc
@@ -62,7 +62,7 @@ class ImageDecodeTaskImpl : public TileTask {
   ImageDecodeTaskImpl(GpuImageDecodeController* controller,
                       const DrawImage& draw_image,
                       const ImageDecodeController::TracingInfo& tracing_info)
-      : TileTask(true),
+      : TileTask(TileTask::Type::IMAGE_DECODE, true),
         controller_(controller),
         image_(draw_image),
         tracing_info_(tracing_info) {
@@ -76,16 +76,12 @@ class ImageDecodeTaskImpl : public TileTask {
     controller_->DecodeImage(image_);
   }
 
-  // Overridden from TileTask:
-  void ScheduleOnOriginThread(RasterBufferProvider* provider) override {}
-  void CompleteOnOriginThread(RasterBufferProvider* provider) override {
-    controller_->DecodeTaskCompleted(image_);
-  }
-
  protected:
   ~ImageDecodeTaskImpl() override {}
 
  private:
+  friend class GpuImageDecodeController;
+
   GpuImageDecodeController* controller_;
   DrawImage image_;
   const ImageDecodeController::TracingInfo tracing_info_;
@@ -102,7 +98,7 @@ class ImageUploadTaskImpl : public TileTask {
                       const DrawImage& draw_image,
                       scoped_refptr<TileTask> decode_dependency,
                       const ImageDecodeController::TracingInfo& tracing_info)
-      : TileTask(false),
+      : TileTask(TileTask::Type::IMAGE_UPLOAD, false),
         controller_(controller),
         image_(draw_image),
         tracing_info_(tracing_info) {
@@ -120,15 +116,12 @@ class ImageUploadTaskImpl : public TileTask {
     controller_->UploadImage(image_);
   }
 
-  void ScheduleOnOriginThread(RasterBufferProvider* provider) override {}
-  void CompleteOnOriginThread(RasterBufferProvider* provider) override {
-    controller_->UploadTaskCompleted(image_);
-  }
-
  protected:
   ~ImageUploadTaskImpl() override {}
 
  private:
+  friend class GpuImageDecodeController;
+
   GpuImageDecodeController* controller_;
   DrawImage image_;
   const ImageDecodeController::TracingInfo tracing_info_;
@@ -367,6 +360,32 @@ void GpuImageDecodeController::SetShouldAggressivelyFreeResources(
   }
 }
 
+void GpuImageDecodeController::OnImageDecodeTaskCompleted(TileTask* task) {
+  base::AutoLock lock(lock_);
+  ImageDecodeTaskImpl* decode_task = static_cast<ImageDecodeTaskImpl*>(task);
+  DCHECK(decode_task);
+  // Decode task is complete, remove it from our list of pending tasks.
+  pending_image_decode_tasks_.erase(decode_task->image_.image()->uniqueID());
+
+  // While the decode task is active, we keep a ref on the decoded data.
+  // Release that ref now.
+  UnrefImageDecode(decode_task->image_);
+}
+
+void GpuImageDecodeController::OnImageUploadTaskCompleted(TileTask* task) {
+  base::AutoLock lock(lock_);
+  ImageUploadTaskImpl* upload_task = static_cast<ImageUploadTaskImpl*>(task);
+  DCHECK(upload_task);
+  // Upload task is complete, remove it from our list of pending tasks.
+  pending_image_upload_tasks_.erase(upload_task->image_.image()->uniqueID());
+
+  // While the upload task is active, we keep a ref on both the image it will be
+  // populating, as well as the decode it needs to populate it. Release these
+  // refs now.
+  UnrefImageDecode(upload_task->image_);
+  UnrefImageInternal(upload_task->image_);
+}
+
 bool GpuImageDecodeController::OnMemoryDump(
     const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
@@ -442,30 +461,6 @@ void GpuImageDecodeController::UploadImage(const DrawImage& draw_image) {
   UploadImageIfNecessary(draw_image, found->second.get());
 }
 
-void GpuImageDecodeController::DecodeTaskCompleted(
-    const DrawImage& draw_image) {
-  base::AutoLock lock(lock_);
-  // Decode task is complete, remove it from our list of pending tasks.
-  pending_image_decode_tasks_.erase(draw_image.image()->uniqueID());
-
-  // While the decode task is active, we keep a ref on the decoded data.
-  // Release that ref now.
-  UnrefImageDecode(draw_image);
-}
-
-void GpuImageDecodeController::UploadTaskCompleted(
-    const DrawImage& draw_image) {
-  base::AutoLock lock(lock_);
-  // Upload task is complete, remove it from our list of pending tasks.
-  pending_image_upload_tasks_.erase(draw_image.image()->uniqueID());
-
-  // While the upload task is active, we keep a ref on both the image it will be
-  // populating, as well as the decode it needs to populate it. Release these
-  // refs now.
-  UnrefImageDecode(draw_image);
-  UnrefImageInternal(draw_image);
-}
-
 // Checks if an existing image decode exists. If not, returns a task to produce
 // the requested decode.
 scoped_refptr<TileTask> GpuImageDecodeController::GetImageDecodeTaskAndRef(