cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/tiles/software_image_decode_controller.cc

Index: cc/tiles/software_image_decode_controller.cc
diff --git a/cc/tiles/software_image_decode_controller.cc b/cc/tiles/software_image_decode_controller.cc
index 86d1bb2c5749430e57378a3a8b49f2c00e14fcde..ea9dc0ef7826a12020482feca26928e45ab21c31 100644
--- a/cc/tiles/software_image_decode_controller.cc
+++ b/cc/tiles/software_image_decode_controller.cc
@@ -79,8 +79,7 @@ class ImageDecodeTaskImpl : public TileTask {
   }
 
   // Overridden from TileTask:
-  void ScheduleOnOriginThread(RasterBufferProvider* provider) override {}
-  void CompleteOnOriginThread(RasterBufferProvider* provider) override {
+  void OnTaskCompleted() override {
     controller_->RemovePendingTask(image_key_);
   }