Avoid copying value in ComputedStyle CoW comparions (compareEqual)

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

Index: third_party/WebKit/Source/core/style/ComputedStyle.h
diff --git a/third_party/WebKit/Source/core/style/ComputedStyle.h b/third_party/WebKit/Source/core/style/ComputedStyle.h
index 6152fa9e3b9a2a33df438d9be6b6be6d076513e4..6dcc03aa5cad8335594833d6a05322ee746b9547 100644
--- a/third_party/WebKit/Source/core/style/ComputedStyle.h
+++ b/third_party/WebKit/Source/core/style/ComputedStyle.h
@@ -82,6 +82,11 @@ inline bool compareEqual(const T& t, const U& u) {
   return t == static_cast<T>(u);
 }
 
+template <typename T>
+inline bool compareEqual(const T& a, const T& b) {
+  return a == b;
+}
+
 #define SET_VAR(group, variable, value)      \
   if (!compareEqual(group->variable, value)) \
   group.access()->variable = value