Add new latency_info for tracking browser composite time.

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 71 matching lines @@
 using blink::WebKeyboardEvent;
 using blink::WebMouseEvent;
 using blink::WebMouseWheelEvent;
 using blink::WebTextDirection;
 
 namespace content {
 namespace {
 
 bool g_check_for_pending_resize_ack = true;
 
+const size_t kBrowserCompositeLatencyHistorySize = 60;
+const double kBrowserCompositeLatencyEstimationPercentile = 90.0;
+
 typedef std::pair<int32, int32> RenderWidgetHostID;
 typedef base::hash_map<RenderWidgetHostID, RenderWidgetHostImpl*>
     RoutingIDWidgetMap;
 base::LazyInstance<RoutingIDWidgetMap> g_routing_id_widget_map =
     LAZY_INSTANCE_INITIALIZER;
 
 int GetInputRouterViewFlagsFromCompositorFrameMetadata(
     const cc::CompositorFrameMetadata metadata) {
   int view_flags = InputRouter::VIEW_FLAGS_NONE;
 
@@ skipping 77 matching lines @@
       input_method_active_(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),
       weak_factory_(this),
       last_input_number_(static_cast<int64>(GetProcess()->GetID()) << 32),
-      next_browser_snapshot_id_(1) {
+      next_browser_snapshot_id_(1),
+      browser_composite_latency_history_(kBrowserCompositeLatencyHistorySize) {
   CHECK(delegate_);
   if (routing_id_ == MSG_ROUTING_NONE) {
     routing_id_ = process_->GetNextRoutingID();
     surface_id_ = GpuSurfaceTracker::Get()->AddSurfaceForRenderer(
         process_->GetID(),
         routing_id_);
   } else {
     // TODO(piman): This is a O(N) lookup, where we could forward the
     // information from the RenderWidgetHelper. The problem is that doing so
     // currently leaks outside of content all the way to chrome classes, and
@@ skipping 1244 matching lines @@
   param.b.AssignTo(frame.get());
   std::vector<IPC::Message> messages_to_deliver_with_frame;
   messages_to_deliver_with_frame.swap(param.c);
 
   for (size_t i = 0; i < frame->metadata.latency_info.size(); i++)
     AddLatencyInfoComponentIds(&frame->metadata.latency_info[i]);
 
   input_router_->OnViewUpdated(
       GetInputRouterViewFlagsFromCompositorFrameMetadata(frame->metadata));
 
+  for (size_t i = 0; i < frame->metadata.latency_info.size(); ++i) {
+    frame->metadata.latency_info[i].AddLatencyNumber(
+        ui::INPUT_EVENT_BROWSER_COMPOSITE_COMPONENT, 0, 0);

[brianderson, 2014/09/18 23:26:15]

If the Browser is swap or commit throttled, there may be a delay from when the
Renderer's swap is received to when it is actually consumed by the Browser.

For deadline estimation purposes, we care about the timing from when the swap is
consumed, not from when it is received.

Not sure where the best place to add an
INPUT_EVENT_RENDERER_SWAP_CONSUMED_COMPONENT is though...

The INPUT_EVENT_BROWSER_COMPOSITE_COMPONENT component would still be useful
though for test/debug purposes, so it might be nice to keep it here. Maybe call
it INPUT_EVENT_RENDERER_SWAP_RECEIVED_COMPONENT though?

[jbauman, 2014/09/19 20:40:29]

This should specify GetLatencyComponentId() as the component ID.

[orglofch, 2014/09/19 22:40:26]

@brian I've renamed the event.

[orglofch, 2014/09/19 22:40:26]

Done.

+  }
+
   if (view_) {
     view_->OnSwapCompositorFrame(output_surface_id, frame.Pass());
     view_->DidReceiveRendererFrame();
   } else {
     cc::CompositorFrameAck ack;
     if (frame->gl_frame_data) {
       ack.gl_frame_data = frame->gl_frame_data.Pass();
       ack.gl_frame_data->sync_point = 0;
     } else if (frame->delegated_frame_data) {
       cc::TransferableResource::ReturnResources(
@@ skipping 671 matching lines @@
         swap_component.event_time - original_component.event_time;
     for (size_t i = 0; i < original_component.event_count; i++) {
       UMA_HISTOGRAM_CUSTOM_COUNTS(
           "Event.Latency.TouchToScrollUpdateSwap",
           delta.InMicroseconds(),
           1,
           1000000,
           100);
     }
   }
+
+  ui::LatencyInfo::LatencyComponent gpu_swap_component;
+  if (!latency_info.FindLatency(
+          ui::INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT, 0, &gpu_swap_component)) {
+    return;
+  }
+
+  ui::LatencyInfo::LatencyComponent composite_component;
+  if (latency_info.FindLatency(ui::INPUT_EVENT_BROWSER_COMPOSITE_COMPONENT,

[jbauman, 2014/09/19 20:40:29]

This should instead find the component with GetLatencyComponentId() as the
component id.

You'll also need to modify RenderWidgetHostImpl::CompositorFrameDrawn to route
the LatencyInfo to the correct RWHI based on that component id for this event.

[orglofch, 2014/09/19 22:40:26]

Done.

+                               0,
+                               &composite_component)) {
+    base::TimeDelta delta =
+        gpu_swap_component.event_time - composite_component.event_time;
+    browser_composite_latency_history_.InsertSample(delta);
+  }
 }
 
 void RenderWidgetHostImpl::DidReceiveRendererFrame() {
   view_->DidReceiveRendererFrame();
 }
 
 void RenderWidgetHostImpl::WindowSnapshotAsyncCallback(
     int routing_id,
     int snapshot_id,
     gfx::Size snapshot_size,
@@ skipping 153 matching lines @@
     RenderWidgetHostImpl::GetRootBrowserAccessibilityManager() {
   return delegate_ ? delegate_->GetRootBrowserAccessibilityManager() : NULL;
 }
 
 BrowserAccessibilityManager*
     RenderWidgetHostImpl::GetOrCreateRootBrowserAccessibilityManager() {
   return delegate_ ?
       delegate_->GetOrCreateRootBrowserAccessibilityManager() : NULL;
 }
 
+base::TimeDelta RenderWidgetHostImpl::GetEstimatedBrowserCompositeTime() {
+  if (browser_composite_latency_history_.SampleCount() > 0) {
+    return browser_composite_latency_history_.Percentile(
+        kBrowserCompositeLatencyEstimationPercentile);
+  } else {
+    return base::TimeDelta::FromMicroseconds(
+        (1.0f * base::Time::kMicrosecondsPerSecond) / (3.0f * 60));
+  }
+}
+
 #if defined(OS_WIN)
 gfx::NativeViewAccessible
     RenderWidgetHostImpl::GetParentNativeViewAccessible() {
   return delegate_ ? delegate_->GetParentNativeViewAccessible() : NULL;
 }
 #endif
 
 SkColorType RenderWidgetHostImpl::PreferredReadbackFormat() {
   if (view_)
     return view_->PreferredReadbackFormat();
   return kN32_SkColorType;
 }
 
 }  // namespace content