submit() in submit event handler should not contains a value of a submit button.

third_party/WebKit/Source/core/html/forms/ImageInputType.cpp

Index: third_party/WebKit/Source/core/html/forms/ImageInputType.cpp
diff --git a/third_party/WebKit/Source/core/html/forms/ImageInputType.cpp b/third_party/WebKit/Source/core/html/forms/ImageInputType.cpp
index beae5acfdd9adbeddbe629a0ea67c433384f4bdd..8774a1325ff3709181f8d7e6a155461b68fb275e 100644
--- a/third_party/WebKit/Source/core/html/forms/ImageInputType.cpp
+++ b/third_party/WebKit/Source/core/html/forms/ImageInputType.cpp
@@ -110,10 +110,8 @@ void ImageInputType::handleDOMActivateEvent(Event* event)
 {
     if (element().isDisabledFormControl() || !element().form())
         return;
-    element().setActivatedSubmit(true);
     m_clickLocation = extractClickLocation(event);
-    element().form()->prepareForSubmission(event); // Event handlers can run.
-    element().setActivatedSubmit(false);
+    element().form()->prepareForSubmission(event, &element()); // Event handlers can run.
     event->setDefaultHandled();
 }