cc: Dump more state in begin main frame hang crash key.

This dumps more state notably including time since last begin frame and
the last few actions.

TBR=brianderson
BUG=622080

Change-Id: I51590aa3e2859b448ca2eafd45046f6f123e9331
Reviewed-on: https://chromium-review.googlesource.com/571286Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486670}

cc/scheduler/scheduler.cc

@@ -12,6 +12,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
+#include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/base/devtools_instrumentation.h"
@@ -270,6 +271,10 @@ void Scheduler::OnBeginFrameSourcePausedChanged(bool paused) {
 bool Scheduler::OnBeginFrameDerivedImpl(const BeginFrameArgs& args) {
   TRACE_EVENT1("cc,benchmark", "Scheduler::BeginFrame", "args", args.AsValue());
 
+  // TEMPORARY: Compositor state for debugging BeginMainFrame renderer hang.
+  // TODO(sunnyps): Remove after fixing https://crbug.com/622080
+  debug_begin_frame_received_at_ = Now();
+
   if (!state_machine_.BeginFrameNeeded()) {
     TRACE_EVENT_INSTANT0("cc", "Scheduler::BeginFrameDropped",
                          TRACE_EVENT_SCOPE_THREAD);
@@ -690,6 +695,12 @@ void Scheduler::ProcessScheduledActions() {
         break;
       }
     }
+
+    // TEMPORARY: Compositor state for debugging BeginMainFrame renderer hang.
+    // TODO(sunnyps): Remove after fixing https://crbug.com/622080
+    if (action != SchedulerStateMachine::ACTION_NONE) {
+      debug_actions_.SaveToBuffer(action);
+    }
   } while (action != SchedulerStateMachine::ACTION_NONE);
 
   ScheduleBeginImplFrameDeadlineIfNeeded();
@@ -697,9 +708,16 @@ void Scheduler::ProcessScheduledActions() {
 
   // TEMPORARY: Compositor state for debugging BeginMainFrame renderer hang.
   // TODO(sunnyps): Remove after fixing https://crbug.com/622080
-  base::debug::SetCrashKeyValue(
-      kBeginMainFrameHangCompositorState,
-      state_machine_.CrashKeyValueForBeginMainFrameHang());
+  std::string state_dump = state_machine_.CrashKeyValueForBeginMainFrameHang();
+  base::StringAppendF(
+      &state_dump, ",%f,%d,%d,%d",
+      (Now() - debug_begin_frame_received_at_).InMillisecondsF(),
+      skipped_last_frame_to_reduce_latency_,
+      skipped_last_frame_missed_exceeded_deadline_, stopped_);
+  for (auto it = debug_actions_.Begin(); it; ++it)
+    base::StringAppendF(&state_dump, ",%d", **it);
+
+  base::debug::SetCrashKeyValue(kBeginMainFrameHangCompositorState, state_dump);
 }
 
 std::unique_ptr<base::trace_event::ConvertableToTraceFormat>

cc/scheduler/scheduler.h

@@ -12,6 +12,7 @@
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "base/time/time.h"
+#include "cc/base/ring_buffer.h"
 #include "cc/cc_export.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/scheduler/begin_frame_source.h"
@@ -198,6 +199,11 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
   SchedulerStateMachine::Action inside_action_ =
       SchedulerStateMachine::ACTION_NONE;
 
+  // TEMPORARY: Compositor state for debugging BeginMainFrame renderer hang.
+  // TODO(sunnyps): Remove after fixing https://crbug.com/622080
+  base::TimeTicks debug_begin_frame_received_at_;
+  RingBuffer<SchedulerStateMachine::Action, 10> debug_actions_;
+
   bool stopped_ = false;
 
  private:

cc/scheduler/scheduler_state_machine.cc

@@ -241,11 +241,12 @@ void SchedulerStateMachine::AsValueInto(
 // TODO(sunnyps): Remove after fixing https://crbug.com/622080
 std::string SchedulerStateMachine::CrashKeyValueForBeginMainFrameHang() const {
   return base::StringPrintf(
-      "%d,%d,%d,%d,%d,%d,%d,%d,%d", begin_impl_frame_state_,
+      "%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d", begin_impl_frame_state_,
       begin_main_frame_state_, layer_tree_frame_sink_state_,
       pending_submit_frames_, visible_, has_pending_tree_,
       pending_tree_is_ready_for_activation_, active_tree_needs_first_draw_,
-      begin_frame_source_paused_);
+      begin_frame_source_paused_, needs_redraw_, needs_prepare_tiles_,
+      needs_one_begin_impl_frame_);
 }
 
 bool SchedulerStateMachine::PendingDrawsShouldBeAborted() const {