Index: third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.h |
diff --git a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.h b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.h |
index 25a5bcd9faa5cb3f5707b936f24a59779595f33d..fb47d824b2b8949868f9534a8010b5327d59d635 100644 |
--- a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.h |
+++ b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.h |
@@ -55,6 +55,20 @@ class PLATFORM_EXPORT DisplayItemClient { |
// offsetFromLayoutObjectWithSubpixelAccumulation(). |
virtual LayoutRect visualRect() const = 0; |
+ // This is declared here instead of in LayoutObject for verifying the |
+ // condition in DrawingRecorder. |
+ // Returns true if the object itself will not generate any effective painted |
+ // output no matter what size the object is. For example, this function can |
+ // return false for an object whose size is currently 0x0 but would have |
+ // effective painted output if it was set a non-empty size. It's used to skip |
+ // unforced paint invalidation of LayoutObjects (which is when |
+ // shouldDoFullPaintInvalidation is false, but mayNeedPaintInvalidation or |
+ // childShouldCheckForPaintInvalidation is true) to avoid unnecessary paint |
+ // invalidations of empty areas covered by such objects. |
+ virtual bool paintedOutputOfObjectHasNoEffectRegardlessOfSize() const { |
+ return false; |
+ } |
+ |
void setDisplayItemsUncached( |
PaintInvalidationReason reason = PaintInvalidationFull) const { |
m_cacheGenerationOrInvalidationReason.invalidate(reason); |