Fix a crash when saving a <canvas> or <img> image which is large.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index a6b4bc45d5482397d36031a44cd0dfc62d1a6e21..69b00724a067a7332cbb80b5c2aba2e7777dd6db 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -40,6 +40,7 @@
 #include "content/child/npapi/webplugin_delegate_impl.h"
 #include "content/child/request_extra_data.h"
 #include "content/child/webmessageportchannel_impl.h"
+#include "content/common/content_constants_internal.h"
 #include "content/common/database_messages.h"
 #include "content/common/dom_storage/dom_storage_types.h"
 #include "content/common/drag_messages.h"
@@ -1723,6 +1724,13 @@ void RenderViewImpl::printPage(WebLocalFrame* frame) {
                     PrintPage(frame, handling_input_event_));
 }
 
+void RenderViewImpl::saveImageFromDataURL(const blink::WebString& data_url) {
+  // Note: We should basically send GURL but we use size-limited string instead
+  // in order to send a larger data url to save a image for <canvas> or <img>.
+  if (data_url.length() < kMaxLengthOfDataURLString)
+    Send(new ViewHostMsg_SaveImageFromDataURL(routing_id_, data_url.utf8()));
+}
+
 bool RenderViewImpl::enumerateChosenDirectory(
     const WebString& path,
     WebFileChooserCompletion* chooser_completion) {