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

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 7c363459516c509561bd2b3ba38caa253d8b5acd..88c0e9e438fbd7462bc5e7b31e71290e647eb396 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -1785,11 +1785,12 @@ void RenderFrameImpl::loadURLExternally(
   if (policy == blink::WebNavigationPolicyDownload) {
     render_view_->Send(new ViewHostMsg_DownloadUrl(render_view_->GetRoutingID(),
                                                    request.url(), referrer,
-                                                   suggested_name, false));
+                                                   suggested_name));
   } else if (policy == blink::WebNavigationPolicyDownloadTo) {
-    render_view_->Send(new ViewHostMsg_DownloadUrl(render_view_->GetRoutingID(),
-                                                   request.url(), referrer,
-                                                   suggested_name, true));
+    render_view_->Send(
+        new ViewHostMsg_SaveImageAs(render_view_->GetRoutingID(),
+                                    request.url().string().utf8(),

[Justin Novosad, 2014/08/29 13:52:32]

So you are just passing the URL as a string to work around the url size limit?
It would be more efficient to pass the binary version of the encoded image,
rather than the data url/base64 version. If that would be a lot more
complicated, then I think this is Okay. This isn't really a performance-critical
area.

[palmer, 2014/08/30 00:37:29]

I agree, just a byte vector is fine.

+                                    referrer, suggested_name));
   } else {
     OpenURL(frame, request.url(), referrer, policy);
   }