Enable print forwarding.

Source/WebCore/bindings/dart/DartNativeUtilities.cpp

Index: Source/WebCore/bindings/dart/DartNativeUtilities.cpp
diff --git a/Source/WebCore/bindings/dart/DartNativeUtilities.cpp b/Source/WebCore/bindings/dart/DartNativeUtilities.cpp
index a4b567fd0a2bf02dc6ba8ba94fc698a330cf12cb..d365063c24978b60bd1fcc50bcfd27f0a1c12473 100644
--- a/Source/WebCore/bindings/dart/DartNativeUtilities.cpp
+++ b/Source/WebCore/bindings/dart/DartNativeUtilities.cpp
@@ -36,7 +36,9 @@
 #include "DartDOMWrapper.h"
 #include "DartDocument.h"
 #include "DartUtilities.h"
+#include "Frame.h"
 #include "RuntimeEnabledFeatures.h"
+#include "V8Converter.h"
 #include "npruntime_impl.h"
 
 #include <bindings/npruntime.h>
@@ -90,6 +92,34 @@ fail:
     ASSERT_NOT_REACHED();
 }
 
+/**
+ * Gadget for testing.
+ *
+ * With DART_FORWARDING_PRINT environment variable set, it invokes dartPrint
+ * JavaScript function on global object to communicate to Dart test framework.
+ */
+static void forwardingPrint(Dart_NativeArguments args)
+{
+    v8::HandleScope v8Scope;
+    ScriptExecutionContext* scriptExecutionContext = DartUtilities::scriptExecutionContext();
+    ASSERT(scriptExecutionContext);
+
+    DartController* dartController = DartController::retrieve(scriptExecutionContext);
+    if (!dartController)
+        return;
+
+    v8::Handle<v8::Context> v8Context = dartController->frame()->script()->mainWorldContext();
+    v8::Context::Scope scope(v8Context);
+    v8::TryCatch tryCatch;
+
+    v8::Handle<v8::Value> function = v8Context->Global()->Get(v8::String::New("dartPrint"));
+    if (function.IsEmpty() || !function->IsFunction())
+        return;
+
+    v8::Handle<v8::Value> message = V8Converter::stringToV8(Dart_GetNativeArgument(args, 0));
+    function.As<v8::Function>()->Call(v8Context->Global(), 1, &message);
+}
+
 static void getNewIsolateId(Dart_NativeArguments args)
 {
     DartApiScope dartApiScope;
@@ -276,6 +306,8 @@ Dart_NativeFunction domResolver(Dart_Handle name, int argumentCount)
         return topLevelWindow;
     if (argumentCount == 1 && str == "Utils_print")
         return print;
+    if (argumentCount == 1 && str == "Utils_forwardingPrint")
+        return forwardingPrint;
     if (argumentCount == 1 && str == "Utils_spawnDomFunction")
         return spawnDomFunction;
     if (argumentCount == 0 && str == "Utils_getNewIsolateId")