Make RenderViewImpl::OnForceRedraw more robust

content/renderer/render_view_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/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <memory>
 
@@ skipping 616 matching lines @@
                               base::CompareCase::SENSITIVE)) {
     return WebSettings::V8CacheStrategiesForCacheStorage::Normal;
   } else if (base::StartsWith(v8_cache_strategies, "aggressive",
                               base::CompareCase::SENSITIVE)) {
     return WebSettings::V8CacheStrategiesForCacheStorage::Aggressive;
   } else {
     return WebSettings::V8CacheStrategiesForCacheStorage::Default;
   }
 }
 
+// This class represents promise which is robust to (will not be broken by)
+// |DidNotSwapReason::SWAP_FAILS| events.
+class CC_EXPORT AlwaysDrawSwapPromise : public cc::SwapPromise {

[danakj, 2016/08/11 21:59:00]

drop the CC_EXPORT

[svartmetal, 2016/08/12 10:07:33]

Fixed.

+ public:
+  explicit AlwaysDrawSwapPromise(const ui::LatencyInfo& latency_info)
+      : latency_info_(latency_info) {}
+
+  ~AlwaysDrawSwapPromise() override = default;
+
+  void DidActivate() override {}
+
+  void DidSwap(cc::CompositorFrameMetadata* metadata) override {
+    DCHECK(!latency_info_.terminated());
+    metadata->latency_info.push_back(latency_info_);
+  }
+
+  DidNotSwapAction DidNotSwap(DidNotSwapReason reason) override {
+    return reason == DidNotSwapReason::SWAP_FAILS
+               ? DidNotSwapAction::KEEP_ACTIVE
+               : DidNotSwapAction::BREAK_PROMISE;
+  }
+
+  void OnCommit() override {}
+
+  int64_t TraceId() const override { return latency_info_.trace_id(); }
+
+ private:
+  ui::LatencyInfo latency_info_;
+};
+
 }  // namespace
 
 RenderViewImpl::RenderViewImpl(CompositorDependencies* compositor_deps,
                                const ViewMsg_New_Params& params)
     : RenderWidget(compositor_deps,
                    blink::WebPopupTypeNone,
                    params.initial_size.screen_info,
                    params.swapped_out,
                    params.hidden,
                    params.never_visible),
@@ skipping 810 matching lines @@
   frames_with_pending_state_.clear();
 }
 
 void RenderViewImpl::ApplyWebPreferencesInternal(
     const WebPreferences& prefs,
     blink::WebView* web_view,
     CompositorDependencies* compositor_deps) {
   ApplyWebPreferences(prefs, web_view);
 }
 
-void RenderViewImpl::OnForceRedraw(int id) {
-  ui::LatencyInfo latency_info;
-  if (id) {
-    latency_info.AddLatencyNumber(ui::WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT,
-                                  0,
-                                  id);
-  }
-  std::unique_ptr<cc::SwapPromiseMonitor> latency_info_swap_promise_monitor;
+void RenderViewImpl::OnForceRedraw(const ui::LatencyInfo& latency_info) {
   if (RenderWidgetCompositor* rwc = compositor()) {
-    latency_info_swap_promise_monitor =
-        rwc->CreateLatencyInfoSwapPromiseMonitor(&latency_info);
+    rwc->QueueSwapPromise(
+        base::WrapUnique(new AlwaysDrawSwapPromise(latency_info)));

[danakj, 2016/08/11 21:59:00]

one last nit: prefer base::MakeUnique<AlwaysDrawSwapPromise>(...) over
base::WrapUnique(new AlwaysDrawSwapPromise(...))

[svartmetal, 2016/08/12 10:07:33]

Fixed.

   }
   ScheduleCompositeWithForcedRedraw();
 }
 
 // blink::WebViewClient ------------------------------------------------------
 
 WebView* RenderViewImpl::createView(WebLocalFrame* creator,
                                     const WebURLRequest& request,
                                     const WebWindowFeatures& features,
                                     const WebString& frame_name,
@@ skipping 1593 matching lines @@
         return render_frame->focused_pepper_plugin();
     }
     frame = frame->traverseNext(false);
   }
 
   return nullptr;
 }
 #endif
 
 }  // namespace content