Refactor StyleVariableData to fallback on root map for performance reasons.

third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.cpp

Index: third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.cpp b/third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.cpp
index eb5f3651ee15f8b772d62a6c99aade25cd5a7483..038d2d3e59915e8f06c4bdd494295f7cc6078717 100644
--- a/third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.cpp
+++ b/third_party/WebKit/Source/core/css/CSSComputedStyleDeclaration.cpp
@@ -29,6 +29,7 @@
 #include "core/css/CSSPropertyMetadata.h"
 #include "core/css/CSSSelector.h"
 #include "core/css/CSSValuePool.h"
+#include "core/css/CSSVariableData.h"

[Timothy Loh, 2016/04/05 03:13:37]

is this needed?

[shans, 2016/04/08 00:55:49]

Yeah. OwnPtr defines a deconstructor, which means we can't just forward-declare
CSSVariableData.

 #include "core/css/ComputedStyleCSSValueMapping.h"
 #include "core/css/parser/CSSParser.h"
 #include "core/css/parser/CSSVariableParser.h"
@@ -534,7 +535,7 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSComputedStyleDeclaration::getPropertyCSSValu
     return ComputedStyleCSSValueMapping::get(customPropertyName, *style);
 }
 
-const HashMap<AtomicString, RefPtr<CSSVariableData>>* CSSComputedStyleDeclaration::getVariables() const
+PassOwnPtr<HashMap<AtomicString, RefPtr<CSSVariableData>>> CSSComputedStyleDeclaration::getVariables() const
 {
     const ComputedStyle* style = computeComputedStyle();
     if (!style)