Add debug BeginFrame tracking

Add some temporary member variables to BeginFrameTracker that stores the
total sent/received and the last 10 sent/received BeginFrameIds. Despite
adding logic to stop sending OnBeginFrame() to unresponsive clients it
didn't help with the large number of unread messages in mojo message
queue. This information will do a better job of verifying if client is
in fact reading (and responding to) the OnBeginFrame() messages.

The |begin_frame_tracker_| is included in a few minidumps I looked at
it, so this information should be available in crash reports. Otherwise
we'll have to copy the information into the stack in OnBeginFrame().

Bug: 1011441
Change-Id: I44112d933fb4470fb037e7bfd2d9dc05dd826a94
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1994093Reviewed-by: Saman Sami <samans@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#730310}

components/viz/service/frame_sinks/begin_frame_tracker.cc

@@ -6,12 +6,22 @@
 
 namespace viz {
 
+BeginFrameTracker::BeginFrameTracker() = default;
+
+BeginFrameTracker::~BeginFrameTracker() = default;
+
 void BeginFrameTracker::SentBeginFrame(const BeginFrameArgs& args) {
+  ++total_begin_frames_sent_;
+  recent_begin_frames_sent_.SaveToBuffer(args.frame_id);
+
   ++outstanding_begin_frames_;
   last_frame_id_ = args.frame_id;
 }
 
 void BeginFrameTracker::ReceivedAck(const BeginFrameAck& ack) {
+  ++total_acks_received_;
+  recent_acks_received_.SaveToBuffer(ack.frame_id);
+
   if (MatchesLastSent(ack)) {
     // If the BeginFrameAck matches the last sent BeginFrameArgs then we know
     // the client has read every message from the pipe. While the client

components/viz/service/frame_sinks/begin_frame_tracker.h

@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_VIZ_SERVICE_FRAME_SINKS_BEGIN_FRAME_TRACKER_H_
 #define COMPONENTS_VIZ_SERVICE_FRAME_SINKS_BEGIN_FRAME_TRACKER_H_
 
+#include "base/containers/ring_buffer.h"
 #include "components/viz/common/frame_sinks/begin_frame_args.h"
 #include "components/viz/service/viz_service_export.h"
 
@@ -23,6 +24,9 @@ class VIZ_SERVICE_EXPORT BeginFrameTracker {
   static constexpr int kLimitStop = 100;
   static constexpr int kLimitThrottle = 10;
 
+  BeginFrameTracker();
+  ~BeginFrameTracker();
+
   // To be called every time OnBeginFrame() is sent.
   void SentBeginFrame(const BeginFrameArgs& args);
 
@@ -38,6 +42,15 @@ class VIZ_SERVICE_EXPORT BeginFrameTracker {
   int outstanding_begin_frames_ = 0;
 
   BeginFrameId last_frame_id_;
+
+  // The following variables are keeping track of some information about sent
+  // and received BeginFrameIds. This information is just being tracked only so
+  // it's available in crash minidumps to help debug https://crbug.com/1011441.
+  // TODO(crbug.com/1011441): Remove this before it hits stable channel!
+  int total_begin_frames_sent_ = 0;
+  int total_acks_received_ = 0;
+  base::RingBuffer<BeginFrameId, 10> recent_begin_frames_sent_;
+  base::RingBuffer<BeginFrameId, 10> recent_acks_received_;
 };
 
 }  // namespace viz