Revert of Add an ASSERT about cross-world wrapper leakage into ScriptValue

Source/web/WebLocalFrameImpl.cpp

Index: Source/web/WebLocalFrameImpl.cpp
diff --git a/Source/web/WebLocalFrameImpl.cpp b/Source/web/WebLocalFrameImpl.cpp
index f5083e2121b94c85a313476359de0e3e669ebaec..f51d641f4d6d534bcc7e607b8899dfa37d5d33d9 100644
--- a/Source/web/WebLocalFrameImpl.cpp
+++ b/Source/web/WebLocalFrameImpl.cpp
@@ -725,7 +725,6 @@
 {
     ASSERT(frame());
     TextPosition position(OrdinalNumber::fromOneBasedInt(source.startLine), OrdinalNumber::first());
-    v8::HandleScope handleScope(toIsolate(frame()));
     frame()->script().executeScriptInMainWorld(ScriptSourceCode(source.code, source.url, position));
 }
 
@@ -808,7 +807,7 @@
     UserGestureIndicator gestureIndicator(DefinitelyProcessingNewUserGesture);
 
     TextPosition position(OrdinalNumber::fromOneBasedInt(source.startLine), OrdinalNumber::first());
-    return frame()->script().executeScriptInMainWorldAndReturnValue(ScriptSourceCode(source.code, source.url, position));
+    return frame()->script().executeScriptInMainWorldAndReturnValue(ScriptSourceCode(source.code, source.url, position)).v8Value();
 }
 
 void WebLocalFrameImpl::executeScriptInIsolatedWorld(int worldID, const WebScriptSource* sourcesIn, unsigned numSources, int extensionGroup, WebVector<v8::Local<v8::Value> >* results)
@@ -825,11 +824,11 @@
     }
 
     if (results) {
-        Vector<v8::Local<v8::Value> > scriptResults;
+        Vector<ScriptValue> scriptResults;
         frame()->script().executeScriptInIsolatedWorld(worldID, sources, extensionGroup, &scriptResults);
         WebVector<v8::Local<v8::Value> > v8Results(scriptResults.size());
         for (unsigned i = 0; i < scriptResults.size(); i++)
-            v8Results[i] = v8::Local<v8::Value>::New(toIsolate(frame()), scriptResults[i]);
+            v8Results[i] = v8::Local<v8::Value>::New(toIsolate(frame()), scriptResults[i].v8Value());
         results->swap(v8Results);
     } else {
         frame()->script().executeScriptInIsolatedWorld(worldID, sources, extensionGroup, 0);
@@ -1861,11 +1860,12 @@
 
     String script = decodeURLEscapeSequences(url.string().substring(strlen("javascript:")));
     UserGestureIndicator gestureIndicator(DefinitelyProcessingNewUserGesture);
-    v8::HandleScope handleScope(toIsolate(frame()));
-    v8::Local<v8::Value> result = frame()->script().executeScriptInMainWorldAndReturnValue(ScriptSourceCode(script));
-    if (result.IsEmpty() || !result->IsString())
-        return;
-    String scriptResult = toCoreString(v8::Handle<v8::String>::Cast(result));
+    ScriptValue result = frame()->script().executeScriptInMainWorldAndReturnValue(ScriptSourceCode(script));
+
+    String scriptResult;
+    if (!result.toString(scriptResult))
+        return;
+
     if (!frame()->navigationScheduler().locationChangePending())
         frame()->document()->loader()->replaceDocument(scriptResult, ownerDocument.get());
 }