cc: Simplify task and its derived classes.

cc/tiles/tile_manager_perftest.cc

Index: cc/tiles/tile_manager_perftest.cc
diff --git a/cc/tiles/tile_manager_perftest.cc b/cc/tiles/tile_manager_perftest.cc
index cc0a41497e9ce839bf102380d67602d93614ffcd..0f51cf9a79a0ad7c45a904c2c1350a9fb6b8cc66 100644
--- a/cc/tiles/tile_manager_perftest.cc
+++ b/cc/tiles/tile_manager_perftest.cc
@@ -10,7 +10,6 @@
 #include "base/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "cc/debug/lap_timer.h"
-#include "cc/raster/raster_buffer.h"
 #include "cc/test/begin_frame_args_test.h"
 #include "cc/test/fake_impl_task_runner_provider.h"
 #include "cc/test/fake_layer_tree_host_impl.h"
@@ -37,28 +36,37 @@ static const int kTimeLimitMillis = 2000;
 static const int kWarmupRuns = 5;
 static const int kTimeCheckInterval = 10;
 
-class FakeTileTaskRunnerImpl : public TileTaskRunner, public TileTaskClient {
+class FakeTileTaskRunnerImpl : public TileTaskRunner {
  public:
+  // Overridden from RasterBufferProvider:
+  scoped_ptr<RasterBuffer> AcquireBufferForRaster(
+      const Resource* resource,
+      uint64_t new_content_id,
+      uint64_t previous_content_id) override {
+    return nullptr;
+  }
+  void ReleaseBufferForRaster(scoped_ptr<RasterBuffer> buffer) override {}
+
   // Overridden from TileTaskRunner:
   void Shutdown() override {}
   void ScheduleTasks(TaskGraph* graph) override {
     for (auto& node : graph->nodes) {
-      TileTask* task = static_cast<TileTask*>(node.task);
+      Task* task = node.task;
 
       task->WillSchedule();
-      task->ScheduleOnOriginThread(this);
+      task->ScheduleOnOriginThread();
       task->DidSchedule();
 
       completed_tasks_.push_back(task);
     }
   }
   void CheckForCompletedTasks() override {
-    for (TileTask::Vector::iterator it = completed_tasks_.begin();
+    for (Task::Vector::iterator it = completed_tasks_.begin();
          it != completed_tasks_.end(); ++it) {
-      TileTask* task = it->get();
+      Task* task = it->get();
 
       task->WillComplete();
-      task->CompleteOnOriginThread(this);
+      task->CompleteOnOriginThread();
       task->DidComplete();
     }
     completed_tasks_.clear();
@@ -70,17 +78,8 @@ class FakeTileTaskRunnerImpl : public TileTaskRunner, public TileTaskClient {
     return ResourceFormatRequiresSwizzle(GetResourceFormat(must_support_alpha));
   }
 
-  // Overridden from TileTaskClient:
-  scoped_ptr<RasterBuffer> AcquireBufferForRaster(
-      const Resource* resource,
-      uint64_t new_content_id,
-      uint64_t previous_content_id) override {
-    return nullptr;
-  }
-  void ReleaseBufferForRaster(scoped_ptr<RasterBuffer> buffer) override {}
-
  private:
-  TileTask::Vector completed_tasks_;
+  Task::Vector completed_tasks_;
 };
 base::LazyInstance<FakeTileTaskRunnerImpl> g_fake_tile_task_runner =
     LAZY_INSTANCE_INITIALIZER;