cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/tiles/tile_manager_unittest.cc

Index: cc/tiles/tile_manager_unittest.cc
diff --git a/cc/tiles/tile_manager_unittest.cc b/cc/tiles/tile_manager_unittest.cc
index 745fee4ca853a48a593c4839a87b8a14602f1d63..a4f26ebee5aa4a2241b55c22190afc55d1e159b2 100644
--- a/cc/tiles/tile_manager_unittest.cc
+++ b/cc/tiles/tile_manager_unittest.cc
@@ -1827,7 +1827,7 @@ class FakeTileTaskRunner : public TileTaskRunner, public TileTaskClient {
 
   // TileTaskRunner methods.
   void Shutdown() override {}
-  void CheckForCompletedTasks() override {}
+  void CollectCompletedTasks(Task::Vector* completed_tasks) override {}
   ResourceFormat GetResourceFormat(bool must_support_alpha) const override {
     return ResourceFormat::RGBA_8888;
   }
@@ -1835,6 +1835,8 @@ class FakeTileTaskRunner : public TileTaskRunner, public TileTaskClient {
     return false;
   }
 
+  TileTaskClient* AsTileTaskClient() override { return this; }
+
   void ScheduleTasks(TaskGraph* graph) override {}
 
   // TileTaskClient methods.
@@ -1855,11 +1857,8 @@ class CancellingTileTaskRunner : public FakeTileTaskRunner {
   ~CancellingTileTaskRunner() override {}
 
   void ScheduleTasks(TaskGraph* graph) override {
-    // Just call CompleteOnOriginThread on each item in the queue. As none of
-    // these items have run yet, they will be treated as cancelled tasks.
-    for (const auto& node : graph->nodes) {
-      static_cast<TileTask*>(node.task)->CompleteOnOriginThread(this);
-    }
+    // Don't do anything. As none of these items have scheduled yet, they will
+    // be treated as cancelled tasks.
   }
 };
 
@@ -1931,15 +1930,7 @@ class VerifyResourceContentIdTileTaskRunner : public FakeTileTaskRunner {
       : expected_resource_id_(expected_resource_id) {}
   ~VerifyResourceContentIdTileTaskRunner() override {}
 
-  void ScheduleTasks(TaskGraph* graph) override {
-    for (const auto& node : graph->nodes) {
-      TileTask* task = static_cast<TileTask*>(node.task);
-      // Triggers a call to AcquireBufferForRaster.
-      task->ScheduleOnOriginThread(this);
-      // Calls TileManager as though task was cancelled.
-      task->CompleteOnOriginThread(this);
-    }
-  }
+  void ScheduleTasks(TaskGraph* graph) override {}
 
   // TileTaskClient methods.
   scoped_ptr<RasterBuffer> AcquireBufferForRaster(