compositor-worker: cc->blink mutation plumbing

third_party/WebKit/Source/core/dom/Element.cpp

Index: third_party/WebKit/Source/core/dom/Element.cpp
diff --git a/third_party/WebKit/Source/core/dom/Element.cpp b/third_party/WebKit/Source/core/dom/Element.cpp
index b13034286d5a965a4bb18eaf55323a18132a2e69..282b18ade30c66c12fe218fa3f21b28fef674f09 100644
--- a/third_party/WebKit/Source/core/dom/Element.cpp
+++ b/third_party/WebKit/Source/core/dom/Element.cpp
@@ -38,6 +38,7 @@
 #include "core/XMLNames.h"
 #include "core/animation/AnimationTimeline.h"
 #include "core/animation/css/CSSAnimations.h"
+#include "core/css/CSSFunctionValue.h"
 #include "core/css/CSSImageValue.h"
 #include "core/css/CSSStyleSheet.h"
 #include "core/css/CSSValuePool.h"
@@ -124,7 +125,9 @@
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/UserGestureIndicator.h"
 #include "platform/graphics/CompositorMutableProperties.h"
+#include "platform/graphics/CompositorMutation.h"
 #include "platform/scroll/ScrollableArea.h"
+#include "platform/transforms/MatrixTransformOperation.h"

[jbroman, 2016/01/23 23:55:09]

This include doesn't seem to be used; am I missing the use?

[majidvp, 2016/01/25 20:40:10]

removed.

 #include "wtf/BitVector.h"
 #include "wtf/HashFunctions.h"
 #include "wtf/text/CString.h"
@@ -994,6 +997,28 @@ void Element::decrementCompositorProxiedProperties(uint32_t mutableProperties)
         setNeedsStyleRecalc(LocalStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::CompositorProxy));
 }
 
+void Element::updateFromMutation(const CompositorMutation& mutation)

[jbroman, 2016/01/23 23:55:09]

Has a core/css/ expert looked at this logic before? If not, I'd suggest having
one (e.g. esprehn, timloh, or rune@opera.com) double-check it.

[majidvp, 2016/01/25 20:40:10]

Not yet, +esprehn@ to check. Basically I see two options for updating the style:
1- Update computed style similar to what happens for compositor-driven CSS
animations
2- Update inline style similar to what happens when user script modifies
element.style.{transform,opacity} in a rAF.

These mutations are coming from user script that is directly manipulating
transform/opacity on the proxies element. So it seemed most appropriate that
they get applied to inline style.

+{
+    ASSERT(isStyledElement());
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("compositor-worker"), "Element::updateFromMutation");
+    // Apply opacity and transform by updating inline style. scroll{Top,Left}
+    // are updated as part of layer tree sync during the commit.
+    if (mutation.isOpacityMutated())
+        setInlineStyleProperty(CSSPropertyOpacity, mutation.opacity(), CSSPrimitiveValue::UnitType::Number);
+    if (mutation.isTransformMutated()) {
+        RefPtrWillBeRawPtr<CSSValueList> valueList(CSSValueList::createSpaceSeparated());
+        RefPtrWillBeRawPtr<CSSFunctionValue> matrixValue(CSSFunctionValue::create(CSSValueMatrix3d));
+        for (int col = 0; col < 4; col++) {
+            for (int row = 0; row < 4; row++) {
+                matrixValue->append(cssValuePool().createValue(mutation.transform().get(row, col), CSSPrimitiveValue::UnitType::Pixels));
+            }
+        }
+        valueList->append(matrixValue.release());
+        ensureMutableInlineStyle().setProperty(CSSPropertyTransform, valueList.release());
+        inlineStyleChanged();
+    }
+}
+
 uint32_t Element::compositorMutableProperties() const
 {
     if (!hasRareData())