Add CompositingReasons to compositor layers.

cc/layers/compositing_reasons.h

+// Copyright 2013 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_COMPOSITING_REASONS_H_
+#define CC_LAYERS_COMPOSITING_REASONS_H_
+
+namespace cc {
+
+// This is a clone of CompositingReasons and WebCompositingReasons from Blink.
+enum {
+  kCompositingReasonUnknown                                = 0,
+  kCompositingReason3DTransform                            = 1 << 0,
+  kCompositingReasonVideo                                  = 1 << 1,
+  kCompositingReasonCanvas                                 = 1 << 2,
+  kCompositingReasonPlugin                                 = 1 << 3,
+  kCompositingReasonIFrame                                 = 1 << 4,
+  kCompositingReasonBackfaceVisibilityHidden               = 1 << 5,
+  kCompositingReasonAnimation                              = 1 << 6,
+  kCompositingReasonFilters                                = 1 << 7,
+  kCompositingReasonPositionFixed                          = 1 << 8,
+  kCompositingReasonPositionSticky                         = 1 << 9,
+  kCompositingReasonOverflowScrollingTouch                 = 1 << 10,
+  kCompositingReasonBlending                               = 1 << 11,
+  kCompositingReasonAssumedOverlap                         = 1 << 12,
+  kCompositingReasonOverlap                                = 1 << 13,
+  kCompositingReasonNegativeZIndexChildren                 = 1 << 14,
+  kCompositingReasonTransformWithCompositedDescendants     = 1 << 15,
+  kCompositingReasonOpacityWithCompositedDescendants       = 1 << 16,
+  kCompositingReasonMaskWithCompositedDescendants          = 1 << 17,
+  kCompositingReasonReflectionWithCompositedDescendants    = 1 << 18,
+  kCompositingReasonFilterWithCompositedDescendants        = 1 << 19,
+  kCompositingReasonBlendingWithCompositedDescendants      = 1 << 20,
+  kCompositingReasonClipsCompositingDescendants            = 1 << 21,
+  kCompositingReasonPerspective                            = 1 << 22,
+  kCompositingReasonPreserve3D                             = 1 << 23,
+  kCompositingReasonReflectionOfCompositedParent           = 1 << 24,
+  kCompositingReasonRoot                                   = 1 << 25,
+  kCompositingReasonLayerForClip                           = 1 << 26,
+  kCompositingReasonLayerForScrollbar                      = 1 << 27,
+  kCompositingReasonLayerForScrollingContainer             = 1 << 28,
+  kCompositingReasonLayerForForeground                     = 1 << 29,
+  kCompositingReasonLayerForBackground                     = 1 << 30,
+  kCompositingReasonLayerForMask                           = 1 << 31,
+};
+
+typedef uint32 CompositingReasons;
+
+}  // namespace cc
+
+#endif  // CC_LAYERS_COMPOSITING_REASONS_H_