Fix unexpected blurry text caused by combination of skew and promotion

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 "wtf/text/WTFString.h"
@@ skipping 80 matching lines @@
                                                                   << 48;
 // Composited layer painted on top of all other layers as decoration
 const uint64_t CompositingReasonLayerForDecoration = UINT64_C(1) << 49;
 
 // Composited elements with inline transforms trigger assumed overlap so that
 // we can update their transforms quickly.
 const uint64_t CompositingReasonInlineTransform = UINT64_C(1) << 50;
 
 const uint64_t CompositingReasonCompositorProxy = UINT64_C(1) << 51;
 
+// Composited elements with counter-skewed text
+const uint64_t CompositingReasonLayerForTextWithinSkewedPromotedElement =

[flackr, 2017/02/25 15:16:19]

nit: how about CompositingReasonSkewWithCompositedSkewedAncestor?

[yigu, 2017/02/27 22:03:42]

Done.

+    UINT64_C(1) << 52;
+
 // 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 |
     CompositingReasonScrollDependentPosition |
     CompositingReasonOverflowScrollingTouch |
     CompositingReasonOverflowScrollingParent |
@@ skipping 18 matching lines @@
     CompositingReasonClipsCompositingDescendants |
     CompositingReasonPositionFixedWithCompositedDescendants;
 
 const uint64_t CompositingReasonCombo3DDescendants =
     CompositingReasonPreserve3DWith3DDescendants |
     CompositingReasonPerspectiveWith3DDescendants;
 
 const uint64_t CompositingReasonComboAllStyleDeterminedReasons =
     CompositingReasonComboAllDirectStyleDeterminedReasons |
     CompositingReasonComboCompositedDescendants |
-    CompositingReasonCombo3DDescendants | CompositingReasonInlineTransform;
+    CompositingReasonCombo3DDescendants | CompositingReasonInlineTransform |
+    CompositingReasonLayerForTextWithinSkewedPromotedElement;
 
 const uint64_t CompositingReasonComboReasonsThatRequireOwnBacking =
     CompositingReasonComboAllDirectReasons | CompositingReasonOverlap |
     CompositingReasonAssumedOverlap | CompositingReasonNegativeZIndexChildren |
     CompositingReasonSquashingDisallowed |
     CompositingReasonTransformWithCompositedDescendants |
     CompositingReasonOpacityWithCompositedDescendants |
     CompositingReasonMaskWithCompositedDescendants |
     CompositingReasonFilterWithCompositedDescendants |
     CompositingReasonBlendingWithCompositedDescendants |
     CompositingReasonIsolateCompositedDescendants |
     CompositingReasonPreserve3DWith3DDescendants |  // preserve-3d has to create
                                                     // a backing store to ensure
                                                     // that 3d-transformed
                                                     // elements intersect.
     CompositingReasonBackdropFilter |
-    CompositingReasonPositionFixedWithCompositedDescendants;
+    CompositingReasonPositionFixedWithCompositedDescendants |
+    CompositingReasonLayerForTextWithinSkewedPromotedElement;
 
 const uint64_t CompositingReasonComboSquashableReasons =
     CompositingReasonOverlap | CompositingReasonAssumedOverlap |
     CompositingReasonOverflowScrollingParent;
 
 typedef uint64_t CompositingReasons;
 
 // Any reasons other than overlap or assumed overlap will require the layer to
 // be separately compositing.
 inline bool requiresCompositing(CompositingReasons reasons) {
@@ skipping 15 matching lines @@
 };
 
 PLATFORM_EXPORT extern const CompositingReasonStringMap
     kCompositingReasonStringMap[];
 PLATFORM_EXPORT extern const size_t kNumberOfCompositingReasons;
 PLATFORM_EXPORT String compositingReasonsAsString(CompositingReasons);
 
 }  // namespace blink
 
 #endif  // CompositingReasons_h