Dismissing the GestureNav overlay after the first non-empty paint to improve UX/responsiveness

content/browser/web_contents/aura/overscroll_navigation_overlay.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/web_contents/aura/overscroll_navigation_overlay.h"
 
 #include "content/browser/frame_host/navigation_entry_impl.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/aura/image_window_delegate.h"
 #include "content/browser/web_contents/web_contents_impl.h"
@@ skipping 138 matching lines @@
   } else {
     window_slider_.reset();
   }
 }
 
 void OverscrollNavigationOverlay::SetupForTesting() {
   need_paint_update_ = false;
 }
 
 void OverscrollNavigationOverlay::StopObservingIfDone() {
-  // If there is a screenshot displayed in the overlay window, then wait for
-  // the navigated page to complete loading and some paint update before
-  // hiding the overlay.
-  // If there is no screenshot in the overlay window, then hide this view
-  // as soon as there is any new painting notification.
-  if ((need_paint_update_ && !received_paint_update_) ||
-      (image_delegate_->has_image() && !loading_complete_)) {
+  // Hide this view as soon as there is any non-empty paint notification.
+  if ((need_paint_update_ && !received_paint_update_)) {
     return;
   }
 
   // If a slide is in progress, then do not destroy the window or the slide.
   if (window_slider_.get() && window_slider_->IsSlideInProgress())
     return;
 
   scoped_ptr<ui::Layer> layer;
   if (window_.get()) {
     layer.reset(window_->AcquireLayer());
@@ skipping 130 matching lines @@
     StopObservingIfDone();
   }
 }
 
 void OverscrollNavigationOverlay::DocumentOnLoadCompletedInMainFrame(
     int32 page_id) {
   // Use the last committed entry rather than the active one, in case a
   // pending entry has been created.
   int committed_entry_id =
       web_contents_->GetController().GetLastCommittedEntry()->GetUniqueID();
-  // For the purposes of dismissing the overlay - consider the loading completed
-  // once the main frame has loaded.
+  // Consider the loading completed once the main frame has loaded.
   if (committed_entry_id == pending_entry_id_ || !pending_entry_id_) {

[sky, 2014/04/01 20:10:23]

nit: no {}

     loading_complete_ = true;
-    StopObservingIfDone();
   }
 }
 
 void OverscrollNavigationOverlay::DidFirstVisuallyNonEmptyPaint(int32 page_id) {
   int visible_entry_id =
       web_contents_->GetController().GetVisibleEntry()->GetUniqueID();
   if (visible_entry_id == pending_entry_id_ || !pending_entry_id_) {
     received_paint_update_ = true;
     StopObservingIfDone();
   }
 }
 
 void OverscrollNavigationOverlay::DidStopLoading(RenderViewHost* host) {
   // Use the last committed entry rather than the active one, in case a
   // pending entry has been created.
   int committed_entry_id =
       web_contents_->GetController().GetLastCommittedEntry()->GetUniqueID();
   if (committed_entry_id == pending_entry_id_ || !pending_entry_id_) {
     loading_complete_ = true;
     if (!received_paint_update_) {
       // Force a repaint after the page is loaded.
       RenderViewHostImpl* view = static_cast<RenderViewHostImpl*>(host);
       view->ScheduleComposite();
     }
-    StopObservingIfDone();
   }
 }
 
 bool OverscrollNavigationOverlay::OnMessageReceived(
     const IPC::Message& message) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   IPC_BEGIN_MESSAGE_MAP(OverscrollNavigationOverlay, message)
     IPC_MESSAGE_HANDLER(ViewHostMsg_UpdateRect, OnUpdateRect)
   IPC_END_MESSAGE_MAP()
   return false;
 }
 
 }  // namespace content