cc: Only send a BeginMainFrame inside an BeginImplFrame.

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/debug/trace_event.h"
@@ skipping 174 matching lines @@
     EXPECT_FALSE(needs_begin_frames());
 
     // Start the initial output surface creation.
     EXPECT_FALSE(scheduler->CanStart());
     scheduler->SetCanStart();
     scheduler->SetVisible(true);
     scheduler->SetCanDraw(true);
     EXPECT_SINGLE_ACTION("ScheduledActionBeginOutputSurfaceCreation", (*this));
     Reset();
 
-    // Finish the initial output surface creation and run the first commit.
+    // We don't see anything happening until the first impl frame.
     scheduler->DidCreateAndInitializeOutputSurface();
     scheduler->SetNeedsCommit();
-    scheduler->NotifyBeginMainFrameStarted();
-    scheduler->NotifyReadyToCommitThenActivateIfNeeded();
+    EXPECT_TRUE(needs_begin_frames());
+    EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
+    Reset();
 
     {
-      SCOPED_TRACE("Go through the motions to draw the commit");
+      SCOPED_TRACE("Do first frame to commit after initialize.");
       AdvanceFrame();
 
+      scheduler->NotifyBeginMainFrameStarted();
+      scheduler->NotifyReadyToCommitThenActivateIfNeeded();
+
       // Run the posted deadline task.
       EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
       task_runner().RunTasksWhile(ImplFrameDeadlinePending(true));
       EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
 
       EXPECT_FALSE(scheduler->CommitPending());
     }
 
     Reset();
 
@@ skipping 1976 matching lines @@
 
   // Deadline task is pending
   EXPECT_TRUE(scheduler->BeginImplFrameDeadlinePending());
   client.task_runner().RunPendingTasks();
   // Deadline task runs immediately
   EXPECT_FALSE(scheduler->BeginImplFrameDeadlinePending());
 }
 
 }  // namespace
 }  // namespace cc