cc: Simplify task and its derived classes.

cc/test/fake_tile_manager.cc

Index: cc/test/fake_tile_manager.cc
diff --git a/cc/test/fake_tile_manager.cc b/cc/test/fake_tile_manager.cc
index 77b9b0dfbcf2d46359d3ad824ee22dc280a5e615..40e376804e2bb16f4a95ec0355a2aad08286538e 100644
--- a/cc/test/fake_tile_manager.cc
+++ b/cc/test/fake_tile_manager.cc
@@ -12,36 +12,43 @@
 
 #include "base/lazy_instance.h"
 #include "base/thread_task_runner_handle.h"
-#include "cc/raster/raster_buffer.h"
 #include "cc/raster/tile_task_runner.h"
 
 namespace cc {
 
 namespace {
 
-class FakeTileTaskRunnerImpl : public TileTaskRunner, public TileTaskClient {
+class FakeTileTaskRunnerImpl : public TileTaskRunner {
  public:
+  // Overridden from RasterBufferProvider:
+  scoped_ptr<RasterBuffer> AcquireBufferForRaster(
+      const Resource* resource,
+      uint64_t resource_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 (const auto& node : graph->nodes) {
-      RasterTask* task = static_cast<RasterTask*>(node.task);
+      Task* task = node.task;
 
       task->WillSchedule();
-      task->ScheduleOnOriginThread(this);
+      task->ScheduleOnOriginThread();
       task->DidSchedule();
 
       completed_tasks_.push_back(task);
     }
   }
   void CheckForCompletedTasks() override {
-    for (RasterTask::Vector::iterator it = completed_tasks_.begin();
-         it != completed_tasks_.end();
-         ++it) {
-      RasterTask* task = it->get();
+    for (Task::Vector::iterator it = completed_tasks_.begin();
+         it != completed_tasks_.end(); ++it) {
+      Task* task = it->get();
 
       task->WillComplete();
-      task->CompleteOnOriginThread(this);
+      task->CompleteOnOriginThread();
       task->DidComplete();
     }
     completed_tasks_.clear();
@@ -53,17 +60,8 @@ class FakeTileTaskRunnerImpl : public TileTaskRunner, public TileTaskClient {
     return ResourceFormatRequiresSwizzle(GetResourceFormat(must_support_alpha));
   }
 
-  // Overridden from TileTaskClient:
-  scoped_ptr<RasterBuffer> AcquireBufferForRaster(
-      const Resource* resource,
-      uint64_t resource_content_id,
-      uint64_t previous_content_id) override {
-    return nullptr;
-  }
-  void ReleaseBufferForRaster(scoped_ptr<RasterBuffer> buffer) override {}
-
  private:
-  RasterTask::Vector completed_tasks_;
+  Task::Vector completed_tasks_;
 };
 base::LazyInstance<FakeTileTaskRunnerImpl> g_fake_tile_task_runner =
     LAZY_INSTANCE_INITIALIZER;