Remove root layer specialness in calculateDrawTransforms

cc/layer_tree_host_unittest.cc

Index: cc/layer_tree_host_unittest.cc
diff --git a/cc/layer_tree_host_unittest.cc b/cc/layer_tree_host_unittest.cc
index 030ee97b14bd78738bdbbd66878d340eb59ff3f2..1a9bdb8020b596d4e381ed6f49a13e43d9a36a49 100644
--- a/cc/layer_tree_host_unittest.cc
+++ b/cc/layer_tree_host_unittest.cc
@@ -651,7 +651,7 @@ public:
 
     virtual void beginTest() OVERRIDE
     {
-        postAddAnimationToMainThread();
+        postAddAnimationToMainThread(m_layerTreeHost->rootLayer());
     }
 
     virtual void afterTest() OVERRIDE
@@ -694,7 +694,7 @@ public:
 
     virtual void beginTest() OVERRIDE
     {
-        postAddAnimationToMainThread();
+        postAddAnimationToMainThread(m_layerTreeHost->rootLayer());
     }
 
     // Use willAnimateLayers to set visible false before the animation runs and
@@ -732,7 +732,7 @@ public:
 
     virtual void beginTest() OVERRIDE
     {
-        postAddAnimationToMainThread();
+        postAddAnimationToMainThread(m_layerTreeHost->rootLayer());
     }
 
     virtual void animateLayers(LayerTreeHostImpl* layerTreeHostImpl, base::TimeTicks monotonicTime) OVERRIDE
@@ -761,40 +761,6 @@ private:
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestAddAnimationWithTimingFunction)
 
-// Ensures that when opacity is being animated, this value does not cause the subtree to be skipped.
-class LayerTreeHostTestDoNotSkipLayersWithAnimatedOpacity : public LayerTreeHostTest {
-public:
-    LayerTreeHostTestDoNotSkipLayersWithAnimatedOpacity()
-    {
-    }
-
-    virtual void beginTest() OVERRIDE
-    {
-        m_layerTreeHost->rootLayer()->setDrawOpacity(1);
-        m_layerTreeHost->setViewportSize(IntSize(10, 10), IntSize(10, 10));
-        m_layerTreeHost->rootLayer()->setOpacity(0);
-        postAddAnimationToMainThread();
-    }
-
-    virtual void commitCompleteOnThread(LayerTreeHostImpl*) OVERRIDE
-    {
-        // If the subtree was skipped when preparing to draw, the layer's draw opacity
-        // will not have been updated. It should be set to 0 due to the animation.
-        // Without the animation, the layer will be skipped since it has zero opacity.
-        EXPECT_EQ(0, m_layerTreeHost->rootLayer()->drawOpacity());
-        endTest();
-    }
-
-    virtual void afterTest() OVERRIDE
-    {
-    }
-};
-
-TEST_F(LayerTreeHostTestDoNotSkipLayersWithAnimatedOpacity, runMultiThread)
-{
-    runTest(true);
-}
-
 // Ensures that main thread animations have their start times synchronized with impl thread animations.
 class LayerTreeHostTestSynchronizeAnimationStartTimes : public LayerTreeHostTest {
 public:
@@ -805,7 +771,7 @@ public:
 
     virtual void beginTest() OVERRIDE
     {
-        postAddAnimationToMainThread();
+        postAddAnimationToMainThread(m_layerTreeHost->rootLayer());
     }
 
     // This is guaranteed to be called before CCLayerTreeHostImpl::animateLayers.
@@ -1240,6 +1206,48 @@ TEST_F(LayerTreeHostTestOpacityChange, runMultiThread)
     runTest(true);
 }
 
+// Ensures that when opacity is being animated, this value does not cause the subtree to be skipped.
+class LayerTreeHostTestDoNotSkipLayersWithAnimatedOpacity : public LayerTreeHostTest {
+public:
+    LayerTreeHostTestDoNotSkipLayersWithAnimatedOpacity()
+        : m_testOpacityChangeDelegate(this)
+        , m_updateCheckLayer(ContentLayerWithUpdateTracking::create(&m_testOpacityChangeDelegate))
+    {
+    }
+
+    virtual void beginTest() OVERRIDE
+    {
+        m_layerTreeHost->setViewportSize(IntSize(10, 10), IntSize(10, 10));
+        m_layerTreeHost->rootLayer()->addChild(m_updateCheckLayer);
+        m_updateCheckLayer->setOpacity(0);
+        m_updateCheckLayer->setDrawOpacity(0);
+        postAddAnimationToMainThread(m_updateCheckLayer.get());
+    }
+
+    virtual void commitCompleteOnThread(LayerTreeHostImpl*) OVERRIDE
+    {
+        endTest();
+    }
+
+    virtual void afterTest() OVERRIDE
+    {
+        // update() should have been called once, proving that the layer was not skipped.
+        EXPECT_EQ(1, m_updateCheckLayer->paintContentsCount());
+
+        // clear m_updateCheckLayer so LayerTreeHost dies.
+        m_updateCheckLayer = NULL;
+    }
+
+private:
+    TestOpacityChangeLayerDelegate m_testOpacityChangeDelegate;
+    scoped_refptr<ContentLayerWithUpdateTracking> m_updateCheckLayer;
+};
+
+TEST_F(LayerTreeHostTestDoNotSkipLayersWithAnimatedOpacity, runMultiThread)
+{
+    runTest(true);
+}
+
 class MockContentLayerClient : public ContentLayerClient {
 public:
     bool drawsContent() const { return true; }