[bindings] Make ScriptValue::v8ValueFor(...) a 'const' method.

R=haraken@chromium.org

Review URL: https://codereview.chromium.org/1305523003

git-svn-id: svn://svn.chromium.org/blink/trunk@200829 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/bindings/core/v8/ScriptValue.cpp

@@ -62,7 +62,7 @@ v8::Local<v8::Value> ScriptValue::v8ValueUnsafe() const
     return m_value->newLocal(isolate());
 }
 
-v8::Local<v8::Value> ScriptValue::v8ValueFor(ScriptState* targetScriptState)
+v8::Local<v8::Value> ScriptValue::v8ValueFor(ScriptState* targetScriptState) const
 {
     if (isEmpty())
         return v8::Local<v8::Value>();

third_party/WebKit/Source/bindings/core/v8/ScriptValue.h

@@ -174,7 +174,7 @@ public:
     // Returns v8Value() if a given ScriptState is the same as the
     // ScriptState which is associated with this ScriptValue. Otherwise
     // this "clones" the v8 value and returns it.
-    v8::Local<v8::Value> v8ValueFor(ScriptState*);
+    v8::Local<v8::Value> v8ValueFor(ScriptState*) const;
 
     bool toString(String&) const;