Implement on demand quad rasterization for PicturePiles.

cc/test/layer_tree_test_common.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/test/layer_tree_test_common.h"
 
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/animation/timing_function.h"
@@ skipping 298 matching lines @@
 }
 
 ThreadedTest::~ThreadedTest()
 {
 }
 
 void ThreadedTest::endTest()
 {
     // For the case where we endTest during beginTest(), set a flag to indicate that
     // the test should end the second beginTest regains control.
-    if (m_beginning)
+    if (m_beginning) {
         m_endWhenBeginReturns = true;
-    else
-        proxy()->MainThread()->PostTask(base::Bind(&ThreadedTest::realEndTest, m_mainThreadWeakPtr));
+    } else {
+        // Racy timeouts and explicit endTest calls might have cleaned up the tree host.
+        if (proxy())

[Leandro Graciá Gil, 2013/03/19 17:30:58]

Found flakiness here when creating the new layer-based pixel test. This should
fix it.

+            proxy()->MainThread()->PostTask(base::Bind(&ThreadedTest::realEndTest, m_mainThreadWeakPtr));
+    }
 }
 
 void ThreadedTest::endTestAfterDelay(int delayMilliseconds)
 {
     proxy()->MainThread()->PostTask(base::Bind(&ThreadedTest::endTest, m_mainThreadWeakPtr));
 }
 
 void ThreadedTest::postAddAnimationToMainThread(Layer* layerToReceiveAnimation)
 {
     proxy()->MainThread()->PostTask(base::Bind(&ThreadedTest::dispatchAddAnimation, m_mainThreadWeakPtr, base::Unretained(layerToReceiveAnimation)));
@@ skipping 186 matching lines @@
     ASSERT_FALSE(m_layerTreeHost.get());
     m_client.reset();
     if (m_timedOut) {
         FAIL() << "Test timed out";
         return;
     }
     afterTest();
 }
 
 }  // namespace cc