Compute accurate screen space bounds for animated layers.

This walks up the layer tree transforming a layer's bounds as a box
through the different layer transforms and uses the
LayerAnimationController::AnimationBoundsForBox to transform the box at
layers which are animated.

Expansion of the box is included for filters which change the bounds,
however, the LayerAnimationController implementation is currently stubbed.

+ Added computation of animation bounds of layers in the screen space.
- Removed invalid assertion in LayerAnimationControllerTest.AnimatedBounds.
~ Renamed methods to use the uniform naming AnimationBounds.
~ Extracted LTHC::ApplySublayerTransformAboutAnchor from
  LTHC::CalculateDrawPropertiesInternal.
~ Fixed LayerImpl::AsValueInto to correctly calculate bounds.
! Did not substitute implementation of ApplySublayerTransformAboutAnchor
  inside CalculateDrawPropertiesInternal due to performance regression.


BUG=280375

Review URL: https://codereview.chromium.org/109193002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246767 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 29 insertions, 0 deletions

diff --git a/cc/layers/layer_utils.h b/cc/layers/layer_utils.h
new file mode 100644
index 0000000..396f070
--- /dev/null
+++ b/cc/layers/layer_utils.h
@@ -0,0 +1,29 @@
+// Copyright 2014 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.
+
+#ifndef CC_LAYERS_LAYER_UTILS_H_
+#define CC_LAYERS_LAYER_UTILS_H_
+
+#include "cc/base/cc_export.h"
+
+namespace gfx {
+  class BoxF;
+}  // namespace gfx
+
+namespace cc {
+  class LayerImpl;
+
+  class CC_EXPORT LayerUtils {
+   public:
+    // Computes a box in screen space that should entirely contain the layer's
+    // bounds through the entirety of the layer's current animation. Returns
+    // true and sets |out| to the inflation if there are animations that can
+    // inflate bounds in the path to the root layer and that it was able to
+    // inflate correctly. Returns false otherwise.
+    static bool GetAnimationBounds(const LayerImpl& layer, gfx::BoxF* out);
+  };
+
+}  // namespace cc
+
+#endif  // CC_LAYERS_LAYER_UTILS_H_