Implement position: sticky updates on compositor

third_party/WebKit/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 "platform/PlatformExport.h"
 #include "wtf/Allocator.h"
 #include <stdint.h>
 
 namespace blink {
 
 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 CompositingReasonPositionFixed                            = UINT64_C(1) << 8;
+const uint64_t CompositingReasonScrollDependentPosition                            = UINT64_C(1) << 8;
 const uint64_t CompositingReasonOverflowScrollingTouch                   = UINT64_C(1) << 9;
 const uint64_t CompositingReasonOverflowScrollingParent                  = UINT64_C(1) << 10;
 const uint64_t CompositingReasonOutOfFlowClipping                        = UINT64_C(1) << 11;
 const uint64_t CompositingReasonVideoOverlay                             = UINT64_C(1) << 12;
 const uint64_t CompositingReasonWillChangeCompositingHint                = UINT64_C(1) << 13;
 const uint64_t CompositingReasonBackdropFilter                           = UINT64_C(1) << 14;
 
 // Overlap reasons that require knowing what's behind you in paint-order before knowing the answer
 const uint64_t CompositingReasonAssumedOverlap                           = UINT64_C(1) << 15;
 const uint64_t CompositingReasonOverlap                                  = UINT64_C(1) << 16;
@@ skipping 45 matching lines @@
 // Various combinations of compositing reasons are defined here also, for more intutive and faster bitwise logic.
 const uint64_t CompositingReasonComboAllDirectReasons =
     CompositingReason3DTransform
     | CompositingReasonVideo
     | CompositingReasonCanvas
     | CompositingReasonPlugin
     | CompositingReasonIFrame
     | CompositingReasonBackfaceVisibilityHidden
     | CompositingReasonActiveAnimation
     | CompositingReasonTransitionProperty
-    | CompositingReasonPositionFixed
+    | CompositingReasonScrollDependentPosition
     | CompositingReasonOverflowScrollingTouch
     | CompositingReasonOverflowScrollingParent
     | CompositingReasonOutOfFlowClipping
     | CompositingReasonVideoOverlay
     | CompositingReasonWillChangeCompositingHint
     | CompositingReasonCompositorProxy
     | CompositingReasonBackdropFilter;
 
 const uint64_t CompositingReasonComboAllDirectStyleDeterminedReasons =
     CompositingReason3DTransform
@@ skipping 66 matching lines @@
     const char* shortName;
     const char* description;
 };
 
 PLATFORM_EXPORT extern const CompositingReasonStringMap kCompositingReasonStringMap[];
 PLATFORM_EXPORT extern const size_t kNumberOfCompositingReasons;
 
 } // namespace blink
 
 #endif // CompositingReasons_h