[WebView] Remove onFailure from VisualStateCallback.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index e6cc05197d3a25613468d2938787f3f54da90757..6f8f33d6058c4f6b0ba8323cd0ae067b213755bd 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -202,10 +202,6 @@ RenderFrameHostImpl::~RenderFrameHostImpl() {
   // the dtor has run.
   swapout_event_monitor_timeout_.reset();
 
-  for (const auto& iter: visual_state_callbacks_) {
-    iter.second.Run(false);
-  }

[boliu, 2015/02/19 18:43:41]

There's a bit inconsistent between renderer and browser shutdown.

In renderer shutdown, all the callback still fire (with COMMIT_FAILS). But now
if browser is shutdown first, all the callbacks are just ignored.

How about keep this block, so at least the content layer guarantees these
callbacks runs no matter what, and it's up for android_webview to decide what to
do in those cases.

[Ignacio Solla, 2015/02/20 11:10:41]

Thanks, good catch. 

So how about do not deliver the callback if the renderer is shuting down? I
think I prefer that option so that the content layer guarantees that these
callbacks only run when the contents are ready. Do you agree? I'm happy to
change it to whatever you want though.

[boliu, 2015/02/20 16:50:55]

+piman to decide

I like hard guarantees over silent "failures". Also I think SwapPromise is used
for other features not related to webview, and I don't know what requirements
those features have about this.

[Ignacio Solla, 2015/02/24 12:49:35]

Done.

-
   if (render_widget_host_)
     render_widget_host_->Cleanup();
 }
@@ -1127,7 +1123,7 @@ void RenderFrameHostImpl::OnJavaScriptExecuteResponse(
 void RenderFrameHostImpl::OnVisualStateResponse(uint64 id) {
   auto it = visual_state_callbacks_.find(id);
   if (it != visual_state_callbacks_.end()) {
-    it->second.Run(true);
+    it->second.Run();
     visual_state_callbacks_.erase(it);
   } else {
     NOTREACHED() << "Received script response for unknown request";