Remove scroll corners and resizers.

sky/engine/platform/graphics/CompositingReasons.h

 // 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 CompositingReasons_h
 #define CompositingReasons_h
 
 #include "platform/PlatformExport.h"
 #include "wtf/MathExtras.h"
 #include <stdint.h>
@@ skipping 46 matching lines @@
 // a layer if anything else in the subtree is composited.
 const uint64_t CompositingReasonRoot                                     = UINT64_C(1) << 39;
 
 // CompositedLayerMapping internal hierarchy reasons
 const uint64_t CompositingReasonLayerForAncestorClip                     = UINT64_C(1) << 40;
 const uint64_t CompositingReasonLayerForDescendantClip                   = UINT64_C(1) << 41;
 const uint64_t CompositingReasonLayerForPerspective                      = UINT64_C(1) << 42;
 const uint64_t CompositingReasonLayerForHorizontalScrollbar              = UINT64_C(1) << 43;
 const uint64_t CompositingReasonLayerForVerticalScrollbar                = UINT64_C(1) << 44;
 const uint64_t CompositingReasonLayerForOverflowControlsHost             = UINT64_C(1) << 45;
-const uint64_t CompositingReasonLayerForScrollCorner                     = UINT64_C(1) << 46;
+// FIXME(sky): 46 is unused.
 const uint64_t CompositingReasonLayerForScrollingContents                = UINT64_C(1) << 47;
 const uint64_t CompositingReasonLayerForScrollingContainer               = UINT64_C(1) << 48;
 const uint64_t CompositingReasonLayerForSquashingContents                = UINT64_C(1) << 49;
 const uint64_t CompositingReasonLayerForSquashingContainer               = UINT64_C(1) << 50;
 const uint64_t CompositingReasonLayerForForeground                       = UINT64_C(1) << 51;
 const uint64_t CompositingReasonLayerForBackground                       = UINT64_C(1) << 52;
 const uint64_t CompositingReasonLayerForMask                             = UINT64_C(1) << 53;
 const uint64_t CompositingReasonLayerForClippingMask                     = UINT64_C(1) << 54;
 const uint64_t CompositingReasonLayerForScrollingBlockSelection          = UINT64_C(1) << 55;
 
@@ skipping 86 matching lines @@
     const char* shortName;
     const char* description;
 };
 
 PLATFORM_EXPORT extern const CompositingReasonStringMap kCompositingReasonStringMap[];
 PLATFORM_EXPORT extern size_t kNumberOfCompositingReasons;
 
 } // namespace blink
 
 #endif // CompositingReasons_h