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 63f77b798b68b32676bd20edadb1310669825842..62058ca4639a15aa101a8a53ccac8b6041c3a2ca 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 events but doesn't allow scripts
+    // to run so we can call it in EventDispatchForbiddenScope scope.

[esprehn, 2014/12/18 06:57:30]

I would be more specific and call out that unload events will fire.

+    EventDispatchForbiddenScope::AllowUserAgentEvents allowEvents;
     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();