cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/test/task_graph_runner_test_template.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TEST_TASK_GRAPH_RUNNER_TEST_TEMPLATE_H_
 #define CC_TEST_TASK_GRAPH_RUNNER_TEST_TEMPLATE_H_
 
 #include "cc/raster/task_graph_runner.h"
 
 #include <vector>
@@ skipping 45 matching lines @@
 
  protected:
   class FakeTaskImpl : public Task {
    public:
     FakeTaskImpl(TaskGraphRunnerTestBase* test, int namespace_index, int id)
         : test_(test), namespace_index_(namespace_index), id_(id) {}
 
     // Overridden from Task:
     void RunOnWorkerThread() override;
 
+    // TODO(prashant.n): Remove this function. crbug.com/599863.
     virtual void CompleteOnOriginThread();
 
    protected:
     ~FakeTaskImpl() override {}
 
    private:
     TaskGraphRunnerTestBase* test_;
     int namespace_index_;
     int id_;
 
@@ skipping 215 matching lines @@
     EXPECT_EQ(1u, this->on_task_completed_ids(i)[0]);
     EXPECT_EQ(0u, this->on_task_completed_ids(i)[1]);
   }
 }
 
 REGISTER_TYPED_TEST_CASE_P(SingleThreadTaskGraphRunnerTest, Priority);
 
 }  // namespace cc
 
 #endif  // CC_TEST_TASK_GRAPH_RUNNER_TEST_TEMPLATE_H_