cc: Remove dangerous LayerImpl::removeFromParent

cc/damage_tracker_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/damage_tracker.h"
 
 #include "cc/layer_impl.h"
 #include "cc/layer_tree_host_common.h"
 #include "cc/math_util.h"
 #include "cc/single_thread_proxy.h"
@@ skipping 543 matching lines @@
 
     // CASE 2: If the layer is removed, its entire old layer becomes exposed, not just the
     //         last update rect.
 
     // Advance one frame without damage so that we know the damage rect is not leftover from the previous case.
     clearDamageForAllSurfaces(root.get());
     emulateDrawingOneFrame(root.get());
     EXPECT_TRUE(root->renderSurface()->damageTracker()->currentDamageRect().IsEmpty());
 
     // Then, test removing child1.
-    child1->removeFromParent();
+    root->removeChild(child1);
+    child1 = NULL;
     emulateDrawingOneFrame(root.get());
     rootDamageRect = root->renderSurface()->damageTracker()->currentDamageRect();
     EXPECT_FLOAT_RECT_EQ(gfx::RectF(100, 100, 30, 30), rootDamageRect);
 }
 
 TEST_F(DamageTrackerTest, verifyDamageForNewUnchangedLayer)
 {
     // If child2 is added to the layer tree, but it doesn't have any explicit damage of
     // its own, it should still indeed damage the target surface.
 
@@ skipping 587 matching lines @@
     EXPECT_TRUE(rootDamageRect.IsEmpty());
 
     // Damage should remain empty even after one frame, since there's yet no new damage
     emulateDrawingOneFrame(root.get());
     rootDamageRect = root->renderSurface()->damageTracker()->currentDamageRect();
     EXPECT_TRUE(rootDamageRect.IsEmpty());
 }
 
 }  // namespace
 }  // namespace cc