Fix restrictions on squashing with incompatible scroll.

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>
 
@@ skipping 16 matching lines @@
 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 CompositingReasonWillChange                             = UINT64_C(1) << 15;
 
 // Overlap reasons that require knowing what's behind you in paint-order before knowing the answer
 const uint64_t CompositingReasonAssumedOverlap                         = UINT64_C(1) << 16;
 const uint64_t CompositingReasonOverlap                                = UINT64_C(1) << 17;
 const uint64_t CompositingReasonNegativeZIndexChildren                 = UINT64_C(1) << 18;
-const uint64_t CompositingReasonOverlapsWithoutSquashingTarget         = UINT64_C(1) << 19;
+const uint64_t CompositingReasonNoSquashingTargetFound                 = UINT64_C(1) << 19;
 
 // Subtree reasons that require knowing what the status of your subtree is before knowing the answer
 const uint64_t CompositingReasonTransformWithCompositedDescendants     = UINT64_C(1) << 20;
 const uint64_t CompositingReasonOpacityWithCompositedDescendants       = UINT64_C(1) << 21;
 const uint64_t CompositingReasonMaskWithCompositedDescendants          = UINT64_C(1) << 22;
 const uint64_t CompositingReasonReflectionWithCompositedDescendants    = UINT64_C(1) << 23;
 const uint64_t CompositingReasonFilterWithCompositedDescendants        = UINT64_C(1) << 24;
 const uint64_t CompositingReasonBlendingWithCompositedDescendants      = UINT64_C(1) << 25;
 const uint64_t CompositingReasonClipsCompositingDescendants            = UINT64_C(1) << 26;
 const uint64_t CompositingReasonPerspectiveWith3DDescendants           = UINT64_C(1) << 27;
@@ skipping 38 matching lines @@
     | CompositingReasonOverflowScrollingParent
     | CompositingReasonOutOfFlowClipping
     | CompositingReasonVideoOverlay
     | CompositingReasonWillChange;
 
 const uint64_t CompositingReasonComboReasonsThatRequireOwnBacking =
     CompositingReasonComboAllDirectReasons
     | CompositingReasonOverlap
     | CompositingReasonAssumedOverlap
     | CompositingReasonNegativeZIndexChildren
-    | CompositingReasonOverlapsWithoutSquashingTarget
+    | CompositingReasonNoSquashingTargetFound
     | CompositingReasonTransformWithCompositedDescendants
     | CompositingReasonOpacityWithCompositedDescendants
     | CompositingReasonMaskWithCompositedDescendants
     | CompositingReasonFilterWithCompositedDescendants
     | CompositingReasonBlendingWithCompositedDescendants
     | CompositingReasonIsolateCompositedDescendants
     | CompositingReasonPreserve3DWith3DDescendants; // preserve-3d has to create backing store to ensure that 3d-transformed elements intersect.
 
 const uint64_t CompositingReasonComboSquashableReasons =
     CompositingReasonOverlap
@@ skipping 61 matching lines @@
         "Has a will-change compositing hint" },
     { CompositingReasonAssumedOverlap,
         "assumedOverlap",
         "Might overlap other composited content" },
     { CompositingReasonOverlap,
         "overlap",
         "Overlaps other composited content" },
     { CompositingReasonNegativeZIndexChildren,
         "negativeZIndexChildren",
         "Parent with composited negative z-index content" },
-    { CompositingReasonOverlapsWithoutSquashingTarget,
-        "overlapsWithoutSquashingTarget",
-        "Cannot be squashed with content immediately behind it" },
+    {  CompositingReasonNoSquashingTargetFound,
+        "noSquashingTargetFound",
+        "Cannot be squashed due to no compatible squashing owner found" },
     { CompositingReasonTransformWithCompositedDescendants,
         "transformWithCompositedDescendants",
         "Has a transform that needs to be known by compositor because of composited descendants" },
     { CompositingReasonOpacityWithCompositedDescendants,
         "opacityWithCompositedDescendants",
         "Has opacity that needs to be applied by compositor because of composited descendants" },
     { CompositingReasonMaskWithCompositedDescendants,
         "maskWithCompositedDescendants",
         "Has a mask that needs to be known by compositor because of composited descendants" },
     { CompositingReasonReflectionWithCompositedDescendants,
@@ skipping 63 matching lines @@
         "layerForMask",
         "Secondary layer, to contain the mask contents" },
     { CompositingReasonLayerForClippingMask,
         "layerForClippingMask",
         "Secondary layer, for clipping mask" }
 };
 
 } // namespace WebCore
 
 #endif // CompositingReasons_h