scheduler: Throttle timers in out-of-view frames

third_party/WebKit/Source/platform/scheduler/renderer/web_frame_scheduler_impl.cc

 // Copyright 2015 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 "platform/scheduler/renderer/web_frame_scheduler_impl.h"
 
 #include "base/trace_event/blame_context.h"
 #include "platform/scheduler/base/real_time_domain.h"
 #include "platform/scheduler/base/virtual_time_domain.h"
 #include "platform/scheduler/child/web_task_runner_impl.h"
 #include "platform/scheduler/renderer/auto_advancing_virtual_time_domain.h"
 #include "platform/scheduler/renderer/renderer_scheduler_impl.h"
 #include "platform/scheduler/renderer/web_view_scheduler_impl.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "public/platform/BlameContext.h"
 #include "public/platform/WebString.h"
 
 namespace blink {
 namespace scheduler {
 
 WebFrameSchedulerImpl::WebFrameSchedulerImpl(
     RendererSchedulerImpl* renderer_scheduler,
     WebViewSchedulerImpl* parent_web_view_scheduler,
     base::trace_event::BlameContext* blame_context)
     : renderer_scheduler_(renderer_scheduler),
       parent_web_view_scheduler_(parent_web_view_scheduler),
       blame_context_(blame_context),
       frame_visible_(true),
-      page_visible_(true) {}
+      page_visible_(true),
+      cross_origin_(false) {}
 
 WebFrameSchedulerImpl::~WebFrameSchedulerImpl() {
   if (loading_task_queue_) {
     loading_task_queue_->UnregisterTaskQueue();
     loading_task_queue_->SetBlameContext(nullptr);
   }
 
   if (timer_task_queue_) {
     timer_task_queue_->UnregisterTaskQueue();
     timer_task_queue_->SetBlameContext(nullptr);
   }
 
   if (unthrottled_task_queue_) {
     unthrottled_task_queue_->UnregisterTaskQueue();
     unthrottled_task_queue_->SetBlameContext(nullptr);
   }
 
   if (parent_web_view_scheduler_)
     parent_web_view_scheduler_->Unregister(this);
 }
 
 void WebFrameSchedulerImpl::DetachFromWebViewScheduler() {
   parent_web_view_scheduler_ = nullptr;
 }
 
 void WebFrameSchedulerImpl::setFrameVisible(bool frame_visible) {
+  DCHECK(parent_web_view_scheduler_);
+  if (frame_visible_ == frame_visible)
+    return;
+  bool was_throttled = ShouldThrottleTimers();
   frame_visible_ = frame_visible;
-  // TODO(alexclarke): Do something with this flag.
+  UpdateTimerThrottling(was_throttled);
+}
+
+void WebFrameSchedulerImpl::setCrossOrigin(bool cross_origin) {
+  DCHECK(parent_web_view_scheduler_);
+  if (cross_origin_ == cross_origin)
+    return;
+  bool was_throttled = ShouldThrottleTimers();
+  cross_origin_ = cross_origin;
+  UpdateTimerThrottling(was_throttled);
 }
 
 blink::WebTaskRunner* WebFrameSchedulerImpl::loadingTaskRunner() {
   DCHECK(parent_web_view_scheduler_);
   if (!loading_web_task_runner_) {
     loading_task_queue_ =
         renderer_scheduler_->NewLoadingTaskRunner("frame_loading_tq");
     loading_task_queue_->SetBlameContext(blame_context_);
     loading_web_task_runner_.reset(new WebTaskRunnerImpl(loading_task_queue_));
   }
   return loading_web_task_runner_.get();
 }
 
 blink::WebTaskRunner* WebFrameSchedulerImpl::timerTaskRunner() {
   DCHECK(parent_web_view_scheduler_);
   if (!timer_web_task_runner_) {
     timer_task_queue_ =
         renderer_scheduler_->NewTimerTaskRunner("frame_timer_tq");
     timer_task_queue_->SetBlameContext(blame_context_);
-    if (!page_visible_) {
+    if (ShouldThrottleTimers()) {
       renderer_scheduler_->throttling_helper()->IncreaseThrottleRefCount(
           timer_task_queue_.get());
     }
     timer_web_task_runner_.reset(new WebTaskRunnerImpl(timer_task_queue_));
   }
   return timer_web_task_runner_.get();
 }
 
 blink::WebTaskRunner* WebFrameSchedulerImpl::unthrottledTaskRunner() {
   DCHECK(parent_web_view_scheduler_);
@@ skipping 26 matching lines @@
   if (background_parser_active)
     parent_web_view_scheduler_->IncrementBackgroundParserCount();
   else
     parent_web_view_scheduler_->DecrementBackgroundParserCount();
 }
 
 void WebFrameSchedulerImpl::setPageVisible(bool page_visible) {
   DCHECK(parent_web_view_scheduler_);
   if (page_visible_ == page_visible)
     return;
+  bool was_throttled = ShouldThrottleTimers();
+  page_visible_ = page_visible;
+  UpdateTimerThrottling(was_throttled);
+}
 
-  page_visible_ = page_visible;
+bool WebFrameSchedulerImpl::ShouldThrottleTimers() const {
+  if (!page_visible_)
+    return true;
+  return RuntimeEnabledFeatures::timerThrottlingForHiddenFramesEnabled() &&
+         !frame_visible_ && cross_origin_;
+}
 
-  if (!timer_web_task_runner_)
+void WebFrameSchedulerImpl::UpdateTimerThrottling(bool was_throttled) {
+  bool should_throttle = ShouldThrottleTimers();
+  if (was_throttled == should_throttle || !timer_web_task_runner_)
     return;
-
-  if (page_visible_) {
-    renderer_scheduler_->throttling_helper()->DecreaseThrottleRefCount(
+  if (should_throttle) {
+    renderer_scheduler_->throttling_helper()->IncreaseThrottleRefCount(
         timer_task_queue_.get());
   } else {
-    renderer_scheduler_->throttling_helper()->IncreaseThrottleRefCount(
+    renderer_scheduler_->throttling_helper()->DecreaseThrottleRefCount(
         timer_task_queue_.get());
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink