cc: Always use SetNeedsBeginFrame to request the next BeginFrame

cc/scheduler/scheduler_unittest.cc

 // Copyright 2011 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.
 
 #include "cc/scheduler/scheduler.h"
 
 #include <string>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 216 matching lines @@
   scheduler->SetNeedsCommit();
 
   // Finish the commit for the first frame.
   scheduler->FinishCommit();
   EXPECT_SINGLE_ACTION("ScheduledActionCommit", client);
   client.Reset();
 
   // Tick should draw but then begin another frame for the second commit.
   scheduler->BeginFrame(BeginFrameArgs::CreateForTesting());
   EXPECT_TRUE(client.needs_begin_frame());
-  EXPECT_ACTION("ScheduledActionDrawAndSwapIfPossible", client, 0, 2);
-  EXPECT_ACTION("ScheduledActionSendBeginFrameToMainThread", client, 1, 2);
+  EXPECT_ACTION("ScheduledActionDrawAndSwapIfPossible", client, 0, 3);
+  EXPECT_ACTION("ScheduledActionSendBeginFrameToMainThread", client, 1, 3);
+  EXPECT_ACTION("SetNeedsBeginFrameOnImplThread", client, 2, 3);

[danakj, 2013/09/12 20:57:29]

Can you update the comment here to explain the new expectation?

   client.Reset();
 
   // Finish the second commit to go back to quiescent state and verify we no
   // longer request BeginFrames.
   scheduler->FinishCommit();
   scheduler->BeginFrame(BeginFrameArgs::CreateForTesting());
   EXPECT_FALSE(client.needs_begin_frame());
 }
 
 TEST(SchedulerTest, TextureAcquisitionCausesCommitInsteadOfDraw) {
@@ skipping 433 matching lines @@
   scheduler->FinishCommit();
   EXPECT_TRUE(client.HasAction("ScheduledActionDrawAndReadback"));
 
   // The replacement commit comes in after 2 readbacks.
   client.Reset();
   scheduler->FinishCommit();
 }
 
 }  // namespace
 }  // namespace cc