cc: Remove safe_to_expect_begin_frame workaround

cc/scheduler/scheduler.cc

 // Copyright 2011 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 "cc/scheduler/scheduler.h"
 
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "cc/debug/traced_value.h"
 
 namespace cc {
 
 Scheduler::Scheduler(SchedulerClient* client,
                      const SchedulerSettings& scheduler_settings)
     : settings_(scheduler_settings),
       client_(client),
       weak_factory_(this),
       last_set_needs_begin_frame_(false),
       has_pending_begin_frame_(false),
-      safe_to_expect_begin_frame_(false),
       state_machine_(scheduler_settings),
       inside_process_scheduled_actions_(false) {
   DCHECK(client_);
   DCHECK(!state_machine_.BeginFrameNeededToDrawByImplThread());
 }
 
 Scheduler::~Scheduler() {
   client_->SetNeedsBeginFrameOnImplThread(false);
 }
 
@@ skipping 59 matching lines @@
   TRACE_EVENT0("cc", "Scheduler::DidLoseOutputSurface");
   state_machine_.DidLoseOutputSurface();
   ProcessScheduledActions();
 }
 
 void Scheduler::DidCreateAndInitializeOutputSurface() {
   TRACE_EVENT0("cc", "Scheduler::DidCreateAndInitializeOutputSurface");
   state_machine_.DidCreateAndInitializeOutputSurface();
   has_pending_begin_frame_ = false;
   last_set_needs_begin_frame_ = false;
-  safe_to_expect_begin_frame_ = false;
   ProcessScheduledActions();
 }
 
 base::TimeTicks Scheduler::AnticipatedDrawTime() {
   TRACE_EVENT0("cc", "Scheduler::AnticipatedDrawTime");
 
   if (!last_set_needs_begin_frame_ ||
       last_begin_frame_args_.interval <= base::TimeDelta())
     return base::TimeTicks();
 
@@ skipping 16 matching lines @@
   // because every SetNeedsBeginFrame will force a redraw.
   bool proactive_begin_frame_wanted =
       state_machine_.ProactiveBeginFrameWantedByImplThread() &&
       !settings_.using_synchronous_renderer_compositor &&
       settings_.throttle_frame_production;
   bool needs_begin_frame = needs_begin_frame_to_draw ||
                            proactive_begin_frame_wanted;
   bool immediate_disables_needed =
       settings_.using_synchronous_renderer_compositor;
 
-  if (needs_begin_frame_to_draw)
-    safe_to_expect_begin_frame_ = true;
-
   // Determine if we need BeginFrame notifications.
   // If we do, always request the BeginFrame immediately.
   // If not, only disable on the next BeginFrame to avoid unnecessary toggles.
   // The synchronous renderer compositor requires immediate disables though.
   if ((needs_begin_frame ||
        state_machine_.inside_begin_frame() ||
        immediate_disables_needed) &&
       (needs_begin_frame != last_set_needs_begin_frame_)) {
     has_pending_begin_frame_ = false;
     client_->SetNeedsBeginFrameOnImplThread(needs_begin_frame);
-    if (safe_to_expect_begin_frame_)
-      last_set_needs_begin_frame_ = needs_begin_frame;
+    last_set_needs_begin_frame_ = needs_begin_frame;
   }
 
   // Request another BeginFrame if we haven't drawn for now until we have
   // deadlines implemented.
   if (state_machine_.inside_begin_frame() && has_pending_begin_frame_) {
     has_pending_begin_frame_ = false;
     client_->SetNeedsBeginFrameOnImplThread(true);
     return;
   }
 }
 
 void Scheduler::BeginFrame(const BeginFrameArgs& args) {
   TRACE_EVENT0("cc", "Scheduler::BeginFrame");
   DCHECK(!has_pending_begin_frame_);
   has_pending_begin_frame_ = true;
-  safe_to_expect_begin_frame_ = true;
   last_begin_frame_args_ = args;
   state_machine_.DidEnterBeginFrame(args);
   ProcessScheduledActions();
   state_machine_.DidLeaveBeginFrame();
 }
 
 void Scheduler::DrawAndSwapIfPossible() {
   DrawSwapReadbackResult result =
       client_->ScheduledActionDrawAndSwapIfPossible();
   state_machine_.DidDrawIfPossibleCompleted(result.did_draw);
@@ skipping 68 matching lines @@
 
   SetupNextBeginFrameIfNeeded();
   client_->DidAnticipatedDrawTimeChange(AnticipatedDrawTime());
 }
 
 bool Scheduler::WillDrawIfNeeded() const {
   return !state_machine_.PendingDrawsShouldBeAborted();
 }
 
 }  // namespace cc