Remove support for CompositingReasonPositionSticky

Source/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 "wtf/MathExtras.h"
 #include <stdint.h>
 
 namespace WebCore {
 
 const uint64_t CompositingReasonNone                                   = 0;
 const uint64_t CompositingReasonAll                                    = ~static_cast<uint64_t>(0);
 
 // Intrinsic reasons that can be known right away by the layer
 const uint64_t CompositingReason3DTransform                            = UINT64_C(1) << 0;
 const uint64_t CompositingReasonVideo                                  = UINT64_C(1) << 1;
 const uint64_t CompositingReasonCanvas                                 = UINT64_C(1) << 2;
 const uint64_t CompositingReasonPlugin                                 = UINT64_C(1) << 3;
 const uint64_t CompositingReasonIFrame                                 = UINT64_C(1) << 4;
 const uint64_t CompositingReasonBackfaceVisibilityHidden               = UINT64_C(1) << 5;
 const uint64_t CompositingReasonActiveAnimation                        = UINT64_C(1) << 6;
 const uint64_t CompositingReasonTransitionProperty                     = UINT64_C(1) << 7;
 const uint64_t CompositingReasonFilters                                = UINT64_C(1) << 8;
 const uint64_t CompositingReasonPositionFixed                          = UINT64_C(1) << 9;
-const uint64_t CompositingReasonPositionSticky                         = UINT64_C(1) << 10;
+// Bit 10 is available.
 const uint64_t CompositingReasonOverflowScrollingTouch                 = UINT64_C(1) << 11;
 const uint64_t CompositingReasonOverflowScrollingParent                = UINT64_C(1) << 12;
 const uint64_t CompositingReasonOutOfFlowClipping                      = UINT64_C(1) << 13;
 const uint64_t CompositingReasonVideoOverlay                           = UINT64_C(1) << 14;
 const uint64_t CompositingReasonWillChangeCompositingHint              = UINT64_C(1) << 15;
 // Bit 16 is available.
 
 // Overlap reasons that require knowing what's behind you in paint-order before knowing the answer
 const uint64_t CompositingReasonAssumedOverlap                         = UINT64_C(1) << 17;
 const uint64_t CompositingReasonOverlap                                = UINT64_C(1) << 18;
@@ skipping 38 matching lines @@
     CompositingReason3DTransform
     | CompositingReasonVideo
     | CompositingReasonCanvas
     | CompositingReasonPlugin
     | CompositingReasonIFrame
     | CompositingReasonBackfaceVisibilityHidden
     | CompositingReasonActiveAnimation
     | CompositingReasonTransitionProperty
     | CompositingReasonFilters
     | CompositingReasonPositionFixed
-    | CompositingReasonPositionSticky
     | CompositingReasonOverflowScrollingTouch
     | CompositingReasonOverflowScrollingParent
     | CompositingReasonOutOfFlowClipping
     | CompositingReasonVideoOverlay
     | CompositingReasonWillChangeCompositingHint;
 
 const uint64_t CompositingReasonComboAllStyleDeterminedReasons =
     CompositingReason3DTransform
     | CompositingReasonBackfaceVisibilityHidden
     | CompositingReasonActiveAnimation
@@ skipping 69 matching lines @@
         "Has an active accelerated animation or transition" },
     { CompositingReasonTransitionProperty,
         "transitionProperty",
         "Has an acceleratable transition property (active or inactive)" },
     { CompositingReasonFilters,
         "filters",
         "Has an accelerated filter" },
     { CompositingReasonPositionFixed,
         "positionFixed",
         "Is fixed position" },
-    { CompositingReasonPositionSticky,
-        "positionSticky",
-        "Is sticky position" },
+    { 0, 0, 0 }, // Available.
     { CompositingReasonOverflowScrollingTouch,
         "overflowScrollingTouch",
         "Is a scrollable overflow element" },
     { CompositingReasonOverflowScrollingParent,
         "overflowScrollingParent",
         "Scroll parent is not an ancestor" },
     { CompositingReasonOutOfFlowClipping,
         "outOfFlowClipping",
         "Has clipping ancestor" },
     { CompositingReasonVideoOverlay,
@@ skipping 91 matching lines @@
         "layerForMask",
         "Secondary layer, to contain the mask contents" },
     { CompositingReasonLayerForClippingMask,
         "layerForClippingMask",
         "Secondary layer, for clipping mask" }
 };
 
 } // namespace WebCore
 
 #endif // CompositingReasons_h