Make NetErrorHelper a RenderFrameObserver.

chrome/renderer/chrome_content_renderer_client.cc

Index: chrome/renderer/chrome_content_renderer_client.cc
diff --git a/chrome/renderer/chrome_content_renderer_client.cc b/chrome/renderer/chrome_content_renderer_client.cc
index 5981a342a3b3a13f687c25d78d6881aa79fee872..fb0579bba8e48fddb2c5b2fa99f70c6be041a831 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -377,6 +377,14 @@ void ChromeContentRendererClient::RenderFrameCreated(
       new prerender::PrerenderHelper(render_frame);
     }
   }
+
+  if (render_frame->GetRenderView()->GetMainRenderFrame() == render_frame) {
+    // Only attach NetErrorHelper to the main frame, since only the main frame
+    // should get error pages.
+    // TODO(ellyjones): when RenderFrame is 1:1 with WebFrame, change this
+    // condition to if (!render_frame()->GetWebFrame()->parent())

[jam, 2014/01/16 16:17:23]

note: this landed yesterday, so you can now do this

+    new NetErrorHelper(render_frame);
+  }
 }
 
 void ChromeContentRendererClient::RenderViewCreated(
@@ -405,8 +413,6 @@ void ChromeContentRendererClient::RenderViewCreated(
     new SearchBox(render_view);
 
   new ChromeRenderViewObserver(render_view, chrome_observer_.get());
-
-  new NetErrorHelper(render_view);
 }
 
 void ChromeContentRendererClient::SetNumberOfViews(int number_of_views) {
@@ -999,7 +1005,14 @@ void ChromeContentRendererClient::GetNavigationErrorStrings(
                                               "t");
       }
     } else {
-      NetErrorHelper* helper = NetErrorHelper::Get(render_view);
+      // TODO(ellyjones): change GetNavigationErrorStrings to take a RenderFrame
+      // instead of a RenderView, then pass that in.
+      // This is safe for now because we only install the NetErrorHelper on the
+      // main render frame anyway; see the TODO(ellyjones) in
+      // RenderFrameCreated.
+      content::RenderFrame* main_render_frame =
+          render_view->GetMainRenderFrame();
+      NetErrorHelper* helper = NetErrorHelper::Get(main_render_frame);

[nasko, 2014/01/14 19:22:15]

helper will be NULL for subframes, so you need to either check for NULL or check
if frame == main_render_frame.

       helper->GetErrorHTML(frame, error, is_post, error_html);
     }
   }