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

content/browser/renderer_host/render_message_filter.cc

Index: content/browser/renderer_host/render_message_filter.cc
diff --git a/content/browser/renderer_host/render_message_filter.cc b/content/browser/renderer_host/render_message_filter.cc
index 13ce2f81908143bf29cb00cdc31c5c8253c351a2..deef39b6fda67ec5f67fe263256d5a11c277565c 100644
--- a/content/browser/renderer_host/render_message_filter.cc
+++ b/content/browser/renderer_host/render_message_filter.cc
@@ -391,6 +391,7 @@ bool RenderMessageFilter::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_LoadFont, OnLoadFont)
 #endif
     IPC_MESSAGE_HANDLER(ViewHostMsg_DownloadUrl, OnDownloadUrl)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_SaveImageAs, OnSaveImageAs)
 #if defined(ENABLE_PLUGINS)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_GetPlugins, OnGetPlugins)
     IPC_MESSAGE_HANDLER(FrameHostMsg_GetPluginInfo, OnGetPluginInfo)
@@ -860,11 +861,11 @@ void RenderMessageFilter::OnGetMonitorColorProfile(std::vector<char>* profile) {
 }
 #endif
 
-void RenderMessageFilter::OnDownloadUrl(int render_view_id,
-                                        const GURL& url,
-                                        const Referrer& referrer,
-                                        const base::string16& suggested_name,
-                                        const bool use_prompt) {
+void RenderMessageFilter::DownloadUrl(int render_view_id,
+                                      const GURL& url,
+                                      const Referrer& referrer,
+                                      const base::string16& suggested_name,
+                                      const bool use_prompt) {
   scoped_ptr<DownloadSaveInfo> save_info(new DownloadSaveInfo());
   save_info->suggested_name = suggested_name;
   save_info->prompt_for_save_location = use_prompt;
@@ -893,6 +894,21 @@ void RenderMessageFilter::OnDownloadUrl(int render_view_id,
       ResourceDispatcherHostImpl::DownloadStartedCallback());
 }
 
+void RenderMessageFilter::OnDownloadUrl(int render_view_id,
+                                        const GURL& url,
+                                        const Referrer& referrer,
+                                        const base::string16& suggested_name) {
+  DownloadUrl(render_view_id, url, referrer, suggested_name, false);
+}
+
+void RenderMessageFilter::OnSaveImageAs(int render_view_id,
+                                        const std::string& encoded_image_data,
+                                        const Referrer& referrer,
+                                        const base::string16& suggested_name) {
+  DownloadUrl(render_view_id, GURL(encoded_image_data),

[Ken Russell (switch to Gerrit), 2014/08/29 23:29:26]

This code needs to check the incoming encoded_image_data's size and return
immediately if it's larger than some large value, like 50 MB or similar. Since
this check is done in exactly one place I think it's fine to define the constant
locally in this method.

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

And do something to make sure the |suggested_name| is OK, transforming it if
necessary.

+      referrer, suggested_name, true);
+}
+
 void RenderMessageFilter::OnCheckNotificationPermission(
     const GURL& source_origin, int* result) {
 #if defined(ENABLE_NOTIFICATIONS)