Enable SVGImage to dispatch events in the destructor.

Source/core/svg/graphics/SVGImage.cpp

Index: Source/core/svg/graphics/SVGImage.cpp
diff --git a/Source/core/svg/graphics/SVGImage.cpp b/Source/core/svg/graphics/SVGImage.cpp
index ad41c4869b097d7c5af06458bd72018f4fb87f07..03b37f5d4ad24c90ccc9823372ccf8f17098fa28 100644
--- a/Source/core/svg/graphics/SVGImage.cpp
+++ b/Source/core/svg/graphics/SVGImage.cpp
@@ -64,6 +64,9 @@ SVGImage::SVGImage(ImageObserver* observer)
 
 SVGImage::~SVGImage()
 {
+    // willBeDestroyed() will fire an unload event against the SVGImage's window object
+    // that can't have listeners so we can call it in EventDispatchForbiddenScope scope.
+    EventDispatchForbiddenScope::AllowUserAgentEvents allowEvents;

[esprehn, 2015/01/09 00:55:06]

Why do you still need this if you have the SVGImage::isInSVGImage check in
closeURL()?

     if (m_page) {
         // Store m_page in a local variable, clearing m_page, so that SVGImageChromeClient knows we're destructed.
         OwnPtrWillBeRawPtr<Page> currentPage = m_page.release();