cc: Simplify Task and its derived classes.

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 6c8bbd7a2720e586c4a1a6cb073718f7adc4a0bd..7a8e3a1063862e0ea6aa27dbf56a5ab08ba604b3 100644
--- a/cc/tiles/software_image_decode_controller.cc
+++ b/cc/tiles/software_image_decode_controller.cc
@@ -16,7 +16,6 @@
 #include "base/thread_task_runner_handle.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "cc/debug/devtools_instrumentation.h"
-#include "cc/raster/tile_task_runner.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkImage.h"
 #include "ui/gfx/skia_util.h"
@@ -41,7 +40,7 @@ class AutoRemoveKeyFromTaskMap {
  public:
   AutoRemoveKeyFromTaskMap(
       std::unordered_map<SoftwareImageDecodeController::ImageKey,
-                         scoped_refptr<ImageDecodeTask>,
+                         scoped_refptr<Task>,
                          SoftwareImageDecodeController::ImageKeyHash>* task_map,
       const SoftwareImageDecodeController::ImageKey& key)
       : task_map_(task_map), key_(key) {}
@@ -49,12 +48,12 @@ class AutoRemoveKeyFromTaskMap {
 
  private:
   std::unordered_map<SoftwareImageDecodeController::ImageKey,
-                     scoped_refptr<ImageDecodeTask>,
+                     scoped_refptr<Task>,
                      SoftwareImageDecodeController::ImageKeyHash>* task_map_;
   SoftwareImageDecodeController::ImageKey key_;
 };
 
-class ImageDecodeTaskImpl : public ImageDecodeTask {
+class ImageDecodeTaskImpl : public Task {
  public:
   ImageDecodeTaskImpl(SoftwareImageDecodeController* controller,
                       const SoftwareImageDecodeController::ImageKey& image_key,
@@ -65,7 +64,7 @@ class ImageDecodeTaskImpl : public ImageDecodeTask {
         image_(image),
         image_ref_(skia::SharePtr(image.image())),
         source_prepare_tiles_id_(source_prepare_tiles_id) {
-    SetTaskTypeId(TASK_TYPE_IMAGE_DECODE);
+    SetTaskType(TASK_TYPE_IMAGE_DECODE);
   }
 
   // Overridden from Task:
@@ -149,7 +148,7 @@ SoftwareImageDecodeController::~SoftwareImageDecodeController() {
 bool SoftwareImageDecodeController::GetTaskForImageAndRef(
     const DrawImage& image,
     uint64_t prepare_tiles_id,
-    scoped_refptr<ImageDecodeTask>* task) {
+    scoped_refptr<Task>* task) {
   // If the image already exists or if we're going to create a task for it, then
   // we'll likely need to ref this image (the exception is if we're prerolling
   // the image only). That means the image is or will be in the cache. When the
@@ -176,7 +175,7 @@ bool SoftwareImageDecodeController::GetTaskForImageAndRef(
   if (!CanHandleImage(key)) {
     base::AutoLock lock(lock_);
     if (prerolled_images_.count(key.image_id()) == 0) {
-      scoped_refptr<ImageDecodeTask>& existing_task = pending_image_tasks_[key];
+      scoped_refptr<Task>& existing_task = pending_image_tasks_[key];
       if (!existing_task) {
         existing_task = make_scoped_refptr(
             new ImageDecodeTaskImpl(this, key, image, prepare_tiles_id));
@@ -209,7 +208,7 @@ bool SoftwareImageDecodeController::GetTaskForImageAndRef(
   }
 
   // If the task exists, return it.
-  scoped_refptr<ImageDecodeTask>& existing_task = pending_image_tasks_[key];
+  scoped_refptr<Task>& existing_task = pending_image_tasks_[key];
   if (existing_task) {
     RefImage(key);
     *task = existing_task;