Make rendering timeouts work even if paint data received early

content/browser/renderer_host/render_widget_host_impl.cc

 // Copyright (c) 2012 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/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <set>
 #include <utility>
 
@@ skipping 179 matching lines @@
       in_get_backing_store_(false),
       ignore_input_events_(false),
       text_direction_updated_(false),
       text_direction_(blink::WebTextDirectionLeftToRight),
       text_direction_canceled_(false),
       suppress_next_char_events_(false),
       pending_mouse_lock_request_(false),
       allow_privileged_mouse_lock_(false),
       has_touch_handler_(false),
       is_in_gesture_scroll_(false),
+      received_paint_after_load_(false),
       next_browser_snapshot_id_(1),
       owned_by_render_frame_host_(false),
       is_focused_(false),
       weak_factory_(this) {
   CHECK(delegate_);
   CHECK_NE(MSG_ROUTING_NONE, routing_id_);
 
   std::pair<RoutingIDWidgetMap::iterator, bool> result =
       g_routing_id_widget_map.Get().insert(std::make_pair(
           RenderWidgetHostID(process->GetID(), routing_id_), this));
@@ skipping 261 matching lines @@
     IPC_MESSAGE_HANDLER(ViewHostMsg_SelectionBoundsChanged,
                         OnSelectionBoundsChanged)
 #if defined(OS_WIN)
     IPC_MESSAGE_HANDLER(ViewHostMsg_WindowlessPluginDummyWindowCreated,
                         OnWindowlessPluginDummyWindowCreated)
     IPC_MESSAGE_HANDLER(ViewHostMsg_WindowlessPluginDummyWindowDestroyed,
                         OnWindowlessPluginDummyWindowDestroyed)
 #endif
     IPC_MESSAGE_HANDLER(InputHostMsg_ImeCompositionRangeChanged,
                         OnImeCompositionRangeChanged)
+    IPC_MESSAGE_HANDLER(ViewHostMsg_DidFirstPaintAfterLoad,
+                        OnFirstPaintAfterLoad)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   if (!handled && input_router_ && input_router_->OnMessageReceived(msg))
     return true;
 
   if (!handled && view_ && view_->OnMessageReceived(msg))
     return true;
 
   return handled;
@@ skipping 422 matching lines @@
     hang_monitor_timeout_->Restart(hung_renderer_delay_);
 }
 
 void RenderWidgetHostImpl::StopHangMonitorTimeout() {
   if (hang_monitor_timeout_)
     hang_monitor_timeout_->Stop();
   RendererIsResponsive();
 }
 
 void RenderWidgetHostImpl::StartNewContentRenderingTimeout() {
+  // It is possible for a compositor frame to arrive before the browser is
+  // notified about the page being committed, in which case no timer is
+  // necessary.
+  if (received_paint_after_load_) {
+    received_paint_after_load_ = false;
+    return;
+  }
+
   if (new_content_rendering_timeout_)

[Charlie Reis, 2015/09/30 21:42:09]

Tangentially related: Why do we need the null check?

[kenrb, 2015/10/01 12:45:09]

I guess we don't. I had originally wanted it in the callback, but I've removed
it here.

     new_content_rendering_timeout_->Start(new_content_rendering_delay_);
 }
 
-void RenderWidgetHostImpl::StopNewContentRenderingTimeout() {
-  if (new_content_rendering_timeout_)
+void RenderWidgetHostImpl::OnFirstPaintAfterLoad() {
+  if (new_content_rendering_timeout_->IsRunning()) {
     new_content_rendering_timeout_->Stop();
+  } else {
+    received_paint_after_load_ = true;
+  }
 }
 
 void RenderWidgetHostImpl::ForwardMouseEvent(const WebMouseEvent& mouse_event) {
   ForwardMouseEventWithLatencyInfo(mouse_event, ui::LatencyInfo());
 }
 
 void RenderWidgetHostImpl::ForwardMouseEventWithLatencyInfo(
       const blink::WebMouseEvent& mouse_event,
       const ui::LatencyInfo& ui_latency) {
   TRACE_EVENT2("input", "RenderWidgetHostImpl::ForwardMouseEvent",
@@ skipping 575 matching lines @@
     Send(new ViewMsg_Move_ACK(routing_id_));
   }
 }
 
 bool RenderWidgetHostImpl::OnSwapCompositorFrame(
     const IPC::Message& message) {
   // This trace event is used in
   // chrome/browser/extensions/api/cast_streaming/performance_test.cc
   TRACE_EVENT0("test_fps,benchmark", "OnSwapCompositorFrame");
 
-  StopNewContentRenderingTimeout();
-
   ViewHostMsg_SwapCompositorFrame::Param param;
   if (!ViewHostMsg_SwapCompositorFrame::Read(&message, &param))
     return false;
   scoped_ptr<cc::CompositorFrame> frame(new cc::CompositorFrame);
   uint32_t output_surface_id = base::get<0>(param);
   base::get<1>(param).AssignTo(frame.get());
   std::vector<IPC::Message> messages_to_deliver_with_frame;
   messages_to_deliver_with_frame.swap(base::get<2>(param));
 
   if (!ui::LatencyInfo::Verify(frame->metadata.latency_info,
@@ skipping 652 matching lines @@
 }
 
 #if defined(OS_WIN)
 gfx::NativeViewAccessible
     RenderWidgetHostImpl::GetParentNativeViewAccessible() {
   return delegate_ ? delegate_->GetParentNativeViewAccessible() : NULL;
 }
 #endif
 
 }  // namespace content