Hook up style invalidation for CSS Paint API.

third_party/WebKit/Source/core/style/ComputedStyle.cpp

Index: third_party/WebKit/Source/core/style/ComputedStyle.cpp
diff --git a/third_party/WebKit/Source/core/style/ComputedStyle.cpp b/third_party/WebKit/Source/core/style/ComputedStyle.cpp
index f1f26471f33d4eab5c6e9dcd5a0c5bce22aa2edd..5c613ad05030ce7230e00581bc8a5f4be3087dbb 100644
--- a/third_party/WebKit/Source/core/style/ComputedStyle.cpp
+++ b/third_party/WebKit/Source/core/style/ComputedStyle.cpp
@@ -22,6 +22,8 @@
 
 #include "core/style/ComputedStyle.h"
 
+#include "core/css/CSSPaintValue.h"
+#include "core/css/CSSPropertyEquality.h"
 #include "core/css/resolver/StyleResolver.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/layout/TextAutosizer.h"
@@ -759,6 +761,36 @@ bool ComputedStyle::diffNeedsPaintInvalidationObject(const ComputedStyle& other)
     if (resize() != other.resize())
         return true;
 
+    if (Vector<Persistent<StyleImage>>* paintImages = rareNonInheritedData->m_paintImages.get()) {

[esprehn, 2016/05/09 21:59:54]

you can just write

if (rareNonInheritedData->m_paintImages)

[ikilpatrick, 2016/05/10 20:39:38]

Done.

+        for (const auto& image : *paintImages) {
+            if (diffNeedsPaintInvalidationObjectForPaintImage(image, other))
+                return true;
+        }
+    }
+
+    return false;
+}
+
+bool ComputedStyle::diffNeedsPaintInvalidationObjectForPaintImage(const StyleImage* image, const ComputedStyle& other) const
+{
+    CSSPaintValue* value = toCSSPaintValue(image->cssValue());
+
+    if (!value->nativeInvalidationProperties() || !value->customInvalidationProperties())
+        return true;

[Timothy Loh, 2016/05/09 07:07:07]

I don't understand why this is true instead of false

[ikilpatrick, 2016/05/10 20:39:38]

Added note:

This is because at style-diff time the CSSPaintValue may not have a backing
CSSPaintImageGenerator yet, we use null 
(creating a CSSPaintImageGenerator requires a document).

+
+    for (CSSPropertyID propertyID : *value->nativeInvalidationProperties()) {
+        if (!CSSPropertyEquality::propertiesEqual(propertyID, *this, other))

[Timothy Loh, 2016/05/09 07:07:07]

For now, I think we should just return true if either isInterpolableProperty or
isShorthandProperty are true, since propertiesEqual handles neither of these yet
(well probably you'll want to handle shorthands here). In particular, I don't
think the checked in code should ever be in a state where we can hit ASSERTs.

[esprehn, 2016/05/09 21:59:54]

Please add TODOs

[ikilpatrick, 2016/05/10 20:39:38]

Tim, did you mean this check? Don't need isShorthandProperty as they are caught
by isInterpolablePropertyCheck.

Added TODO to remove once we have full coverage in CSSPropertyEquality

[Timothy Loh, 2016/05/11 06:20:37]

looks fine

+            return true;
+    }
+
+    for (const AtomicString& property : *value->customInvalidationProperties()) {
+        CSSVariableData* thisVar = variables() ? variables()->getVariable(property) : nullptr;

[esprehn, 2016/05/09 21:59:54]

you can early out this before the loop too.

if (static_cast<bool>(variables()) != static_cast<bool>(other.variables()))
  return true;
if (variables()) {
  for (...) {
    ...
  }
}

[ikilpatrick, 2016/05/10 20:39:38]

Not strictly correct as you could have:
this->variables = { '--bar': '2' }
other->variables = null;
value->customInvalidationProperties() = [ '--foo' ];

Added check if they are both null.

+        CSSVariableData* otherVar = other.variables() ? other.variables()->getVariable(property) : nullptr;
+
+        if (!dataEquivalent(thisVar, otherVar))
+            return true;
+    }
+
     return false;
 }
 
@@ -816,6 +848,13 @@ void ComputedStyle::updatePropertySpecificDifferences(const ComputedStyle& other
     }
 }
 
+void ComputedStyle::addPaintImage(StyleImage* image)
+{
+    if (!rareNonInheritedData.access()->m_paintImages)
+        rareNonInheritedData.access()->m_paintImages = adoptPtr(new Vector<Persistent<StyleImage>>());
+    rareNonInheritedData.access()->m_paintImages->append(image);
+}
+
 void ComputedStyle::addCursor(StyleImage* image, bool hotSpotSpecified, const IntPoint& hotSpot)
 {
     if (!rareInheritedData.access()->cursorData)