Reland of Fixed the audio backgrounding bug

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index ff87202bcccaf9b7b6daa3be1592569b477f4287..c6f6a5a2d00b0d5f8fb97938a322317df39a4d03 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -259,9 +259,8 @@
     ResourceContext** resource_context_out,
     net::URLRequestContext** request_context_out) {
   *resource_context_out = resource_context;
-  *request_context_out =
-      GetRequestContext(request_context, media_request_context,
-                        request.resource_type);
+  *request_context_out = GetRequestContext(
+      request_context, media_request_context, request.resource_type);
 }
 
 #if defined(ENABLE_WEBRTC)
@@ -278,8 +277,8 @@
   base::File dump_file(file_path,
                        base::File::FLAG_OPEN_ALWAYS | base::File::FLAG_APPEND);
   if (!dump_file.IsValid()) {
-    VLOG(1) << "Could not open AEC dump file, error=" <<
-               dump_file.error_details();
+    VLOG(1) << "Could not open AEC dump file, error="
+            << dump_file.error_details();
     return IPC::InvalidPlatformFileForTransit();
   }
   return IPC::TakeFileHandleForProcess(dump_file.Pass(), process);
@@ -292,8 +291,8 @@
 #endif
 
 // the global list of all renderer processes
-base::LazyInstance<IDMap<RenderProcessHost> >::Leaky
-    g_all_hosts = LAZY_INSTANCE_INITIALIZER;
+base::LazyInstance<IDMap<RenderProcessHost>>::Leaky g_all_hosts =
+    LAZY_INSTANCE_INITIALIZER;
 
 // Map of site to process, to ensure we only have one RenderProcessHost per
 // site in process-per-site mode.  Each map is specific to a BrowserContext.
@@ -317,14 +316,12 @@
     // Find all instances of this process in the map, then separately remove
     // them.
     std::set<std::string> sites;
-    for (SiteToProcessMap::const_iterator i = map_.begin();
-         i != map_.end();
+    for (SiteToProcessMap::const_iterator i = map_.begin(); i != map_.end();
          i++) {
       if (i->second == host)
         sites.insert(i->first);
     }
-    for (std::set<std::string>::iterator i = sites.begin();
-         i != sites.end();
+    for (std::set<std::string>::iterator i = sites.begin(); i != sites.end();
          i++) {
       SiteToProcessMap::iterator iter = map_.find(*i);
       if (iter != map_.end()) {
@@ -358,7 +355,8 @@
 #if defined(OS_POSIX)
       : ipc_fd_(channel->TakeClientFileDescriptor())
 #endif  // OS_POSIX
-  {}
+  {
+  }
 
   ~RendererSandboxedProcessLauncherDelegate() override {}
 
@@ -386,9 +384,7 @@
   base::ScopedFD TakeIpcFd() override { return ipc_fd_.Pass(); }
 #endif  // OS_WIN
 
-  SandboxType GetSandboxType() override {
-    return SANDBOX_TYPE_RENDERER;
-  }
+  SandboxType GetSandboxType() override { return SANDBOX_TYPE_RENDERER; }
 
  private:
 #if defined(OS_POSIX)
@@ -412,7 +408,7 @@
   }
 
  private:
-  std::map<int, SessionStorageNamespaceMap >
+  std::map<int, SessionStorageNamespaceMap>
       session_storage_namespaces_awaiting_close_;
   DISALLOW_COPY_AND_ASSIGN(SessionStorageHolder);
 };
@@ -434,7 +430,7 @@
 base::MessageLoop* g_in_process_thread;
 
 base::MessageLoop*
-    RenderProcessHostImpl::GetInProcessRendererThreadForTesting() {
+RenderProcessHostImpl::GetInProcessRendererThreadForTesting() {
   return g_in_process_thread;
 }
 
@@ -508,7 +504,7 @@
       pending_views_(0),
       mojo_application_host_(new MojoApplicationHost),
       visible_widgets_(0),
-      backgrounded_(true),
+      is_process_backgrounded_(false),
       is_initialized_(false),
       id_(ChildProcessHostImpl::GenerateChildProcessUniqueId()),
       browser_context_(browser_context),
@@ -553,11 +549,6 @@
   if (BootstrapSandboxManager::ShouldEnable())
     AddObserver(BootstrapSandboxManager::GetInstance());
 #endif
-
-  // Note: When we create the RenderProcessHostImpl, it's technically
-  //       backgrounded, because it has no visible listeners.  But the process
-  //       doesn't actually exist yet, so we'll Background it later, after
-  //       creation.
 }
 
 // static
@@ -570,8 +561,7 @@
     case 1: {
       RenderProcessHostImpl* host = static_cast<RenderProcessHostImpl*>(
           AllHostsIterator().GetCurrentValue());
-      FOR_EACH_OBSERVER(RenderProcessHostObserver,
-                        host->observers_,
+      FOR_EACH_OBSERVER(RenderProcessHostObserver, host->observers_,
                         RenderProcessHostDestroyed(host));
 #ifndef NDEBUG
       host->is_self_deleted_ = true;
@@ -617,7 +607,7 @@
   UnregisterHost(GetID());
 
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kDisableGpuShaderDiskCache)) {
+          switches::kDisableGpuShaderDiskCache)) {
     BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
                             base::Bind(&RemoveShaderInfo, GetID()));
   }
@@ -642,8 +632,8 @@
       browser_command_line.GetSwitchValueNative(switches::kRendererCmdPrefix);
 
 #if defined(OS_LINUX)
-  int flags = renderer_prefix.empty() ? ChildProcessHost::CHILD_ALLOW_SELF :
-                                        ChildProcessHost::CHILD_NORMAL;
+  int flags = renderer_prefix.empty() ? ChildProcessHost::CHILD_ALLOW_SELF
+                                      : ChildProcessHost::CHILD_NORMAL;
 #else
   int flags = ChildProcessHost::CHILD_NORMAL;
 #endif
@@ -681,8 +671,9 @@
     // on separate threads.
     in_process_renderer_.reset(
         g_renderer_main_thread_factory(InProcessChildThreadParams(
-            channel_id, BrowserThread::UnsafeGetMessageLoopForThread(
-                            BrowserThread::IO)->task_runner())));
+            channel_id,
+            BrowserThread::UnsafeGetMessageLoopForThread(BrowserThread::IO)
+                ->task_runner())));
 
     base::Thread::Options options;
 #if defined(OS_WIN) && !defined(OS_MACOSX)
@@ -717,10 +708,8 @@
     // As long as there's no renderer prefix, we can use the zygote process
     // at this stage.
     child_process_launcher_.reset(new ChildProcessLauncher(
-        new RendererSandboxedProcessLauncherDelegate(channel_.get()),
-        cmd_line,
-        GetID(),
-        this));
+        new RendererSandboxedProcessLauncherDelegate(channel_.get()), cmd_line,
+        GetID(), this));
 
     fast_shutdown_started_ = false;
   }
@@ -743,7 +732,7 @@
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO);
   scoped_refptr<base::SequencedTaskRunner> mojo_task_runner =
       BrowserThread::UnsafeGetMessageLoopForThread(BrowserThread::IO)
-            ->task_runner();
+          ->task_runner();
   if (ShouldUseMojoChannel()) {
     VLOG(1) << "Mojo Channel is enabled on host";
 
@@ -772,12 +761,9 @@
 
   scoped_refptr<RenderMessageFilter> render_message_filter(
       new RenderMessageFilter(
-          GetID(),
-          GetBrowserContext(),
+          GetID(), GetBrowserContext(),
           GetBrowserContext()->GetRequestContextForRenderProcess(GetID()),
-          widget_helper_.get(),
-          audio_manager,
-          media_internals,
+          widget_helper_.get(), audio_manager, media_internals,
           storage_partition_impl_->GetDOMStorageContext()));
   AddFilter(render_message_filter.get());
   AddFilter(new RenderFrameMessageFilter(
@@ -817,33 +803,25 @@
   // The AudioInputRendererHost and AudioRendererHost needs to be available for
   // lookup, so it's stashed in a member variable.
   audio_input_renderer_host_ = new AudioInputRendererHost(
-      GetID(),
-      base::GetProcId(GetHandle()),
-      audio_manager,
-      media_stream_manager,
-      AudioMirroringManager::GetInstance(),
+      GetID(), base::GetProcId(GetHandle()), audio_manager,
+      media_stream_manager, AudioMirroringManager::GetInstance(),
       BrowserMainLoop::GetInstance()->user_input_monitor());
   AddFilter(audio_input_renderer_host_.get());
   audio_renderer_host_ = new AudioRendererHost(
-      GetID(),
-      audio_manager,
-      AudioMirroringManager::GetInstance(),
-      media_internals,
-      media_stream_manager,
+      GetID(), audio_manager, AudioMirroringManager::GetInstance(),
+      media_internals, media_stream_manager,
       browser_context->GetResourceContext()->GetMediaDeviceIDSalt());
   AddFilter(audio_renderer_host_.get());
   AddFilter(
       new MidiHost(GetID(), BrowserMainLoop::GetInstance()->midi_manager()));
   AddFilter(new VideoCaptureHost(media_stream_manager));
   AddFilter(new AppCacheDispatcherHost(
-      storage_partition_impl_->GetAppCacheService(),
-      GetID()));
+      storage_partition_impl_->GetAppCacheService(), GetID()));
   AddFilter(new ClipboardMessageFilter);
   AddFilter(new DOMStorageMessageFilter(
       storage_partition_impl_->GetDOMStorageContext()));
   AddFilter(new IndexedDBDispatcherHost(
-      GetID(),
-      storage_partition_impl_->GetURLRequestContext(),
+      GetID(), storage_partition_impl_->GetURLRequestContext(),
       storage_partition_impl_->GetIndexedDBContext(),
       ChromeBlobStorageContext::GetFor(browser_context)));
 
@@ -851,14 +829,12 @@
   AddFilter(gpu_message_filter_);
 #if defined(ENABLE_WEBRTC)
   AddFilter(new WebRTCIdentityServiceHost(
-      GetID(),
-      storage_partition_impl_->GetWebRTCIdentityStore(),
+      GetID(), storage_partition_impl_->GetWebRTCIdentityStore(),
       resource_context));
   peer_connection_tracker_host_ = new PeerConnectionTrackerHost(GetID());
   AddFilter(peer_connection_tracker_host_.get());
   AddFilter(new MediaStreamDispatcherHost(
-      GetID(),
-      browser_context->GetResourceContext()->GetMediaDeviceIDSalt(),
+      GetID(), browser_context->GetResourceContext()->GetMediaDeviceIDSalt(),
       media_stream_manager));
   AddFilter(new MediaStreamTrackMetricsHost());
 #endif
@@ -868,15 +844,14 @@
   AddFilter(new SpeechRecognitionDispatcherHost(
       GetID(), storage_partition_impl_->GetURLRequestContext()));
   AddFilter(new FileAPIMessageFilter(
-      GetID(),
-      storage_partition_impl_->GetURLRequestContext(),
+      GetID(), storage_partition_impl_->GetURLRequestContext(),
       storage_partition_impl_->GetFileSystemContext(),
       ChromeBlobStorageContext::GetFor(browser_context),
       StreamContext::GetFor(browser_context)));
   AddFilter(new FileUtilitiesMessageFilter(GetID()));
   AddFilter(new MimeRegistryMessageFilter());
-  AddFilter(new DatabaseMessageFilter(
-      storage_partition_impl_->GetDatabaseTracker()));
+  AddFilter(
+      new DatabaseMessageFilter(storage_partition_impl_->GetDatabaseTracker()));
 #if defined(OS_MACOSX)
   AddFilter(new TextInputClientMessageFilter(GetID()));
 #elif defined(OS_WIN)
@@ -895,8 +870,8 @@
 
   WebSocketDispatcherHost::GetRequestContextCallback
       websocket_request_context_callback(
-          base::Bind(&GetRequestContext, request_context,
-                     media_request_context, RESOURCE_TYPE_SUB_RESOURCE));
+          base::Bind(&GetRequestContext, request_context, media_request_context,
+                     RESOURCE_TYPE_SUB_RESOURCE));
 
   AddFilter(
       new WebSocketDispatcherHost(GetID(), websocket_request_context_callback));
@@ -919,8 +894,7 @@
   AddFilter(service_worker_filter.get());
 
   AddFilter(new SharedWorkerMessageFilter(
-      GetID(),
-      resource_context,
+      GetID(), resource_context,
       WorkerStoragePartition(
           storage_partition_impl_->GetURLRequestContext(),
           storage_partition_impl_->GetMediaURLRequestContext(),
@@ -943,15 +917,12 @@
   AddFilter(new ResolveProxyMsgHelper(
       browser_context->GetRequestContextForRenderProcess(GetID())));
   AddFilter(new QuotaDispatcherHost(
-      GetID(),
-      storage_partition_impl_->GetQuotaManager(),
+      GetID(), storage_partition_impl_->GetQuotaManager(),
       GetContentClient()->browser()->CreateQuotaPermissionContext()));
 
   notification_message_filter_ = new NotificationMessageFilter(
-      GetID(),
-      storage_partition_impl_->GetPlatformNotificationContext(),
-      resource_context,
-      browser_context);
+      GetID(), storage_partition_impl_->GetPlatformNotificationContext(),
+      resource_context, browser_context);
   AddFilter(notification_message_filter_.get());
 
   AddFilter(new GamepadBrowserMessageFilter());
@@ -1054,10 +1025,9 @@
                                                  const gpu::ValueState& state) {
   DCHECK(subscribe_uniform_enabled_);
   if (subscription_set_.find(target) != subscription_set_.end()) {
-    GpuProcessHost::SendOnIO(
-        GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
-        CAUSE_FOR_GPU_LAUNCH_NO_LAUNCH,
-        new GpuMsg_UpdateValueState(id_, target, state));
+    GpuProcessHost::SendOnIO(GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
+                             CAUSE_FOR_GPU_LAUNCH_NO_LAUNCH,
+                             new GpuMsg_UpdateValueState(id_, target, state));
   } else {
     // Store the ValueState locally in case a Valuebuffer subscribes to it later
     pending_valuebuffer_state_->UpdateState(target, state);
@@ -1075,11 +1045,10 @@
 }
 #endif
 
-void RenderProcessHostImpl::AddRoute(
-    int32 routing_id,
-    IPC::Listener* listener) {
-  CHECK(!listeners_.Lookup(routing_id))
-      << "Found Routing ID Conflict: " << routing_id;
+void RenderProcessHostImpl::AddRoute(int32 routing_id,
+                                     IPC::Listener* listener) {
+  CHECK(!listeners_.Lookup(routing_id)) << "Found Routing ID Conflict: "
+                                        << routing_id;
   listeners_.AddWithID(listener, routing_id);
 }
 
@@ -1117,28 +1086,29 @@
 }
 
 void RenderProcessHostImpl::WidgetRestored() {
-  // Verify we were properly backgrounded.
-  DCHECK_EQ(backgrounded_, (visible_widgets_ == 0));
   visible_widgets_++;
-  SetBackgrounded(false);
+  UpdateProcessPriority();
+  DCHECK(!is_process_backgrounded_);
 }
 
 void RenderProcessHostImpl::WidgetHidden() {
-  // On startup, the browser will call Hide
-  if (backgrounded_)
+  // On startup, the browser will call Hide. We ignore this call.
+  if (visible_widgets_ == 0)
     return;
 
-  DCHECK_EQ(backgrounded_, (visible_widgets_ == 0));
-  visible_widgets_--;
-  DCHECK_GE(visible_widgets_, 0);
+  --visible_widgets_;
   if (visible_widgets_ == 0) {
-    DCHECK(!backgrounded_);
-    SetBackgrounded(true);
+    DCHECK(!is_process_backgrounded_);
+    UpdateProcessPriority();
   }
 }
 
 int RenderProcessHostImpl::VisibleWidgetCount() const {
   return visible_widgets_;
+}
+
+void RenderProcessHostImpl::AudioStateChanged() {
+  UpdateProcessPriority();
 }
 
 bool RenderProcessHostImpl::IsForGuestsOnly() const {
@@ -1162,9 +1132,8 @@
 
   int msaa_sample_count = GpuRasterizationMSAASampleCount();
   if (msaa_sample_count >= 0) {
-    command_line->AppendSwitchASCII(
-        switches::kGpuRasterizationMSAASampleCount,
-        base::IntToString(msaa_sample_count));
+    command_line->AppendSwitchASCII(switches::kGpuRasterizationMSAASampleCount,
+                                    base::IntToString(msaa_sample_count));
   }
 
   if (IsZeroCopyUploadEnabled())
@@ -1226,8 +1195,8 @@
                                     field_trial_states);
   }
 
-  GetContentClient()->browser()->AppendExtraCommandLineSwitches(
-      command_line, GetID());
+  GetContentClient()->browser()->AppendExtraCommandLineSwitches(command_line,
+                                                                GetID());
 
   if (IsPinchToZoomEnabled())
     command_line->AppendSwitch(switches::kEnablePinch);
@@ -1516,8 +1485,7 @@
   if (!GetContentClient()->browser()->IsFastShutdownPossible())
     return false;
 
-  if (!child_process_launcher_.get() ||
-      child_process_launcher_->IsStarting() ||
+  if (!child_process_launcher_.get() || child_process_launcher_->IsStarting() ||
       !GetHandle())
     return false;  // Render process hasn't started or is probably crashed.
 
@@ -1588,9 +1556,9 @@
       IPC_MESSAGE_HANDLER(AecDumpMsg_UnregisterAecDumpConsumer,
                           OnUnregisterAecDumpConsumer)
 #endif
-      // Adding single handlers for your service here is fine, but once your
-      // service needs more than one handler, please extract them into a new
-      // message filter and add that filter to CreateMessageFilters().
+    // Adding single handlers for your service here is fine, but once your
+    // service needs more than one handler, please extract them into a new
+    // message filter and add that filter to CreateMessageFilters().
     IPC_END_MESSAGE_MAP()
 
     return true;
@@ -1647,11 +1615,9 @@
   // Inform AudioInputRendererHost about the new render process PID.
   // AudioInputRendererHost is reference counted, so it's lifetime is
   // guarantueed during the lifetime of the closure.
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&AudioInputRendererHost::set_renderer_pid,
-                 audio_input_renderer_host_,
-                 peer_pid));
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+                          base::Bind(&AudioInputRendererHost::set_renderer_pid,
+                                     audio_input_renderer_host_, peer_pid));
 }
 
 void RenderProcessHostImpl::OnChannelError() {
@@ -1738,13 +1704,11 @@
     DCHECK(!deleting_soon_);
 
     DCHECK_EQ(0, pending_views_);
-    FOR_EACH_OBSERVER(RenderProcessHostObserver,
-                      observers_,
+    FOR_EACH_OBSERVER(RenderProcessHostObserver, observers_,
                       RenderProcessHostDestroyed(this));
     NotificationService::current()->Notify(
         NOTIFICATION_RENDERER_PROCESS_TERMINATED,
-        Source<RenderProcessHost>(this),
-        NotificationService::NoDetails());
+        Source<RenderProcessHost>(this), NotificationService::NoDetails());
 
 #ifndef NDEBUG
     is_self_deleted_ = true;
@@ -1813,8 +1777,7 @@
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   // Enable AEC dump for each registered consumer.
-  base::FilePath file_with_extensions =
-      GetAecDumpFilePathWithExtensions(file);
+  base::FilePath file_with_extensions = GetAecDumpFilePathWithExtensions(file);
   for (std::vector<int>::iterator it = aec_dump_consumers_.begin();
        it != aec_dump_consumers_.end(); ++it) {
     EnableAecDumpForId(file_with_extensions, *it);
@@ -1825,8 +1788,7 @@
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&AudioInputRendererHost::EnableDebugRecording,
-                 audio_input_renderer_host_,
-                 file));
+                 audio_input_renderer_host_, file));
 }
 
 void RenderProcessHostImpl::DisableAudioDebugRecordings() {
@@ -1836,8 +1798,7 @@
   // for avoiding races between enable and disable. Nothing is done on the FILE
   // thread.
   BrowserThread::PostTaskAndReply(
-      BrowserThread::FILE, FROM_HERE,
-      base::Bind(&DisableAecDumpOnFileThread),
+      BrowserThread::FILE, FROM_HERE, base::Bind(&DisableAecDumpOnFileThread),
       base::Bind(&RenderProcessHostImpl::SendDisableAecDumpToRenderer,
                  weak_factory_.GetWeakPtr()));
 
@@ -1845,9 +1806,8 @@
   // guaranteed during the lifetime of the closure.
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
-      base::Bind(
-          &AudioInputRendererHost::DisableDebugRecording,
-          audio_input_renderer_host_));
+      base::Bind(&AudioInputRendererHost::DisableDebugRecording,
+                 audio_input_renderer_host_));
 }
 
 void RenderProcessHostImpl::SetWebRtcLogMessageCallback(
@@ -1863,13 +1823,10 @@
   if (!p2p_socket_dispatcher_host_.get())
     return WebRtcStopRtpDumpCallback();
 
-  BrowserThread::PostTask(BrowserThread::IO,
-                          FROM_HERE,
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
                           base::Bind(&P2PSocketDispatcherHost::StartRtpDump,
-                                     p2p_socket_dispatcher_host_,
-                                     incoming,
-                                     outgoing,
-                                     packet_callback));
+                                     p2p_socket_dispatcher_host_, incoming,
+                                     outgoing, packet_callback));
 
   if (stop_rtp_dump_callback_.is_null()) {
     stop_rtp_dump_callback_ =
@@ -1951,7 +1908,8 @@
 
   // Do not allow browser plugin guests to navigate to non-web URLs, since they
   // cannot swap processes or grant bindings.
-  bool non_web_url_in_guest = rph->IsForGuestsOnly() &&
+  bool non_web_url_in_guest =
+      rph->IsForGuestsOnly() &&
       !(url->is_valid() && policy->IsWebSafeScheme(url->scheme()));
 
   if (non_web_url_in_guest || !policy->CanRequestURL(rph->GetID(), *url)) {
@@ -1964,10 +1922,9 @@
 }
 
 // static
-bool RenderProcessHostImpl::IsSuitableHost(
-    RenderProcessHost* host,
-    BrowserContext* browser_context,
-    const GURL& site_url) {
+bool RenderProcessHostImpl::IsSuitableHost(RenderProcessHost* host,
+                                           BrowserContext* browser_context,
+                                           const GURL& site_url) {
   if (run_renderer_in_process())
     return true;
 
@@ -2039,7 +1996,8 @@
 
 // static
 bool RenderProcessHost::ShouldTryToUseExistingProcessHost(
-    BrowserContext* browser_context, const GURL& url) {
+    BrowserContext* browser_context,
+    const GURL& url) {
   // If --site-per-process is enabled, do not try to reuse renderer processes
   // when over the limit.
   // TODO(nick): This is overly conservative and isn't launchable. Move this
@@ -2060,8 +2018,8 @@
   if (g_all_hosts.Get().size() >= GetMaxRendererProcessCount())
     return true;
 
-  return GetContentClient()->browser()->
-      ShouldTryToUseExistingProcessHost(browser_context, url);
+  return GetContentClient()->browser()->ShouldTryToUseExistingProcessHost(
+      browser_context, url);
 }
 
 // static
@@ -2075,9 +2033,8 @@
   iterator iter(AllHostsIterator());
   while (!iter.IsAtEnd()) {
     if (GetContentClient()->browser()->MayReuseHost(iter.GetCurrentValue()) &&
-        RenderProcessHostImpl::IsSuitableHost(
-            iter.GetCurrentValue(),
-            browser_context, site_url)) {
+        RenderProcessHostImpl::IsSuitableHost(iter.GetCurrentValue(),
+                                              browser_context, site_url)) {
       suitable_renderers.push_back(iter.GetCurrentValue());
     }
     iter.Advance();
@@ -2094,9 +2051,8 @@
 }
 
 // static
-bool RenderProcessHost::ShouldUseProcessPerSite(
-    BrowserContext* browser_context,
-    const GURL& url) {
+bool RenderProcessHost::ShouldUseProcessPerSite(BrowserContext* browser_context,
+                                                const GURL& url) {
   // Returns true if we should use the process-per-site model.  This will be
   // the case if the --process-per-site switch is specified, or in
   // process-per-site-instance for particular sites (e.g., WebUI).
@@ -2125,13 +2081,12 @@
     BrowserContext* browser_context,
     const GURL& url) {
   // Look up the map of site to process for the given browser_context.
-  SiteProcessMap* map =
-      GetSiteProcessMapForBrowserContext(browser_context);
+  SiteProcessMap* map = GetSiteProcessMapForBrowserContext(browser_context);
 
   // See if we have an existing process with appropriate bindings for this site.
   // If not, the caller should create a new process and register it.
-  std::string site = SiteInstance::GetSiteForURL(browser_context, url)
-      .possibly_invalid_spec();
+  std::string site =
+      SiteInstance::GetSiteForURL(browser_context, url).possibly_invalid_spec();
   RenderProcessHost* host = map->FindProcess(site);
   if (host && (!GetContentClient()->browser()->MayReuseHost(host) ||
                !IsSuitableHost(host, browser_context, url))) {
@@ -2151,14 +2106,13 @@
     RenderProcessHost* process,
     const GURL& url) {
   // Look up the map of site to process for the given browser_context.
-  SiteProcessMap* map =
-      GetSiteProcessMapForBrowserContext(browser_context);
+  SiteProcessMap* map = GetSiteProcessMapForBrowserContext(browser_context);
 
   // Only register valid, non-empty sites.  Empty or invalid sites will not
   // use process-per-site mode.  We cannot check whether the process has
   // appropriate bindings here, because the bindings have not yet been granted.
-  std::string site = SiteInstance::GetSiteForURL(browser_context, url)
-      .possibly_invalid_spec();
+  std::string site =
+      SiteInstance::GetSiteForURL(browser_context, url).possibly_invalid_spec();
   if (!site.empty())
     map->RegisterProcess(site, process);
 }
@@ -2208,14 +2162,14 @@
     delete queued_messages_.front();
     queued_messages_.pop();
   }
+  UpdateProcessPriority();
+  DCHECK(!is_process_backgrounded_);
 
   within_process_died_observer_ = true;
   NotificationService::current()->Notify(
-      NOTIFICATION_RENDERER_PROCESS_CLOSED,
-      Source<RenderProcessHost>(this),
+      NOTIFICATION_RENDERER_PROCESS_CLOSED, Source<RenderProcessHost>(this),
       Details<RendererClosedDetails>(&details));
-  FOR_EACH_OBSERVER(RenderProcessHostObserver,
-                    observers_,
+  FOR_EACH_OBSERVER(RenderProcessHostObserver, observers_,
                     RenderProcessExited(this, status, exit_code));
   within_process_died_observer_ = false;
 
@@ -2229,10 +2183,8 @@
 
   IDMap<IPC::Listener>::iterator iter(&listeners_);
   while (!iter.IsAtEnd()) {
-    iter.GetCurrentValue()->OnMessageReceived(
-        FrameHostMsg_RenderProcessGone(iter.GetCurrentKey(),
-                                       static_cast<int>(status),
-                                       exit_code));
+    iter.GetCurrentValue()->OnMessageReceived(FrameHostMsg_RenderProcessGone(
+        iter.GetCurrentKey(), static_cast<int>(status), exit_code));
     iter.Advance();
   }
 
@@ -2272,13 +2224,11 @@
   DCHECK(host);
   if (sessions.empty())
     return;
-  SessionStorageHolder* holder = static_cast<SessionStorageHolder*>
-      (host->GetUserData(kSessionStorageHolderKey));
+  SessionStorageHolder* holder = static_cast<SessionStorageHolder*>(
+      host->GetUserData(kSessionStorageHolderKey));
   if (!holder) {
     holder = new SessionStorageHolder();
-    host->SetUserData(
-        kSessionStorageHolderKey,
-        holder);
+    host->SetUserData(kSessionStorageHolderKey, holder);
   }
   holder->Hold(sessions, view_route_id);
 }
@@ -2304,24 +2254,29 @@
   SetSuddenTerminationAllowed(enabled);
 }
 
-void RenderProcessHostImpl::SetBackgrounded(bool backgrounded) {
-  TRACE_EVENT1("renderer_host", "RenderProcessHostImpl::SetBackgrounded",
-               "backgrounded", backgrounded);
-  // Note: we always set the backgrounded_ value.  If the process is NULL
-  // (and hence hasn't been created yet), we will set the process priority
-  // later when we create the process.
-  backgrounded_ = backgrounded;
-  if (!child_process_launcher_.get() || child_process_launcher_->IsStarting())
+void RenderProcessHostImpl::UpdateProcessPriority() {
+  if (!child_process_launcher_.get() || child_process_launcher_->IsStarting()) {
+    is_process_backgrounded_ = false;
     return;
-
-  // Don't background processes which have active audio streams.
-  if (backgrounded_ && audio_renderer_host_->HasActiveAudio())
+  }
+
+  // We background a process as soon as it hosts no active audio streams and no
+  // visible widgets -- the callers must call this function whenever we
+  // transition in/out of those states.
+  const bool should_background =
+      visible_widgets_ == 0 && !audio_renderer_host_->HasActiveAudio() &&
+      !base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableRendererBackgrounding);
+
+// TODO(sebsg): Remove this ifdef when https://crbug.com/537671 is fixed.
+#if !defined(OS_ANDROID)
+  if (is_process_backgrounded_ == should_background)
     return;
-
-  const base::CommandLine* command_line =
-      base::CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kDisableRendererBackgrounding))
-    return;
+#endif
+
+  TRACE_EVENT1("renderer_host", "RenderProcessHostImpl::UpdateProcessPriority",
+               "should_background", should_background);
+  is_process_backgrounded_ = should_background;
 
 #if defined(OS_WIN)
   // The cbstext.dll loads as a global GetMessage hook in the browser process
@@ -2339,10 +2294,10 @@
   // tasks executing at lowered priority ahead of it or simply by not being
   // swiftly scheduled by the OS per the low process priority
   // (http://crbug.com/398103).
-  child_process_launcher_->SetProcessBackgrounded(backgrounded);
+  child_process_launcher_->SetProcessBackgrounded(should_background);
 
   // Notify the child process of background state.
-  Send(new ChildProcessMsg_SetProcessBackgrounded(backgrounded));
+  Send(new ChildProcessMsg_SetProcessBackgrounded(should_background));
 }
 
 void RenderProcessHostImpl::OnProcessLaunched() {
@@ -2365,7 +2320,15 @@
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "465841 RenderProcessHostImpl::OnProcessLaunched::Backgrounded"));
     DCHECK(child_process_launcher_->GetProcess().IsValid());
-    SetBackgrounded(backgrounded_);
+    DCHECK(!is_process_backgrounded_);
+
+    // Not all platforms launch processes in the same backgrounded state. Make
+    // sure |is_process_backgrounded_| reflects this platform's initial process
+    // state.
+    is_process_backgrounded_ =
+        child_process_launcher_->GetProcess().IsProcessBackgrounded();
+
+    UpdateProcessPriority();
   }
 
   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/465841
@@ -2380,10 +2343,9 @@
   // The queued messages contain such things as "navigate". If this notification
   // was after, we can end up executing JavaScript before the initialization
   // happens.
-  NotificationService::current()->Notify(
-      NOTIFICATION_RENDERER_PROCESS_CREATED,
-      Source<RenderProcessHost>(this),
-      NotificationService::NoDetails());
+  NotificationService::current()->Notify(NOTIFICATION_RENDERER_PROCESS_CREATED,
+                                         Source<RenderProcessHost>(this),
+                                         NotificationService::NoDetails());
 
   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/465841
   // is fixed.
@@ -2442,13 +2404,12 @@
     return;
 
   // TODO(wfh): Fill in the real error code here see crbug.com/526198.
-  RendererClosedDetails details { base::TERMINATION_STATUS_LAUNCH_FAILED,
-                                  -1 };
+  RendererClosedDetails details{base::TERMINATION_STATUS_LAUNCH_FAILED, -1};
   ProcessDied(true, &details);
 }
 
-scoped_refptr<AudioRendererHost>
-RenderProcessHostImpl::audio_renderer_host() const {
+scoped_refptr<AudioRendererHost> RenderProcessHostImpl::audio_renderer_host()
+    const {
   return audio_renderer_host_;
 }
 
@@ -2458,8 +2419,8 @@
 }
 
 void RenderProcessHostImpl::OnCloseACK(int old_route_id) {
-  SessionStorageHolder* holder = static_cast<SessionStorageHolder*>
-      (GetUserData(kSessionStorageHolderKey));
+  SessionStorageHolder* holder =
+      static_cast<SessionStorageHolder*>(GetUserData(kSessionStorageHolderKey));
   if (!holder)
     return;
   holder->Release(old_route_id);
@@ -2489,22 +2450,16 @@
 #if defined(ENABLE_WEBRTC)
 void RenderProcessHostImpl::OnRegisterAecDumpConsumer(int id) {
   BrowserThread::PostTask(
-      BrowserThread::UI,
-      FROM_HERE,
-      base::Bind(
-          &RenderProcessHostImpl::RegisterAecDumpConsumerOnUIThread,
-          weak_factory_.GetWeakPtr(),
-          id));
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&RenderProcessHostImpl::RegisterAecDumpConsumerOnUIThread,
+                 weak_factory_.GetWeakPtr(), id));
 }
 
 void RenderProcessHostImpl::OnUnregisterAecDumpConsumer(int id) {
   BrowserThread::PostTask(
-      BrowserThread::UI,
-      FROM_HERE,
-      base::Bind(
-          &RenderProcessHostImpl::UnregisterAecDumpConsumerOnUIThread,
-          weak_factory_.GetWeakPtr(),
-          id));
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&RenderProcessHostImpl::UnregisterAecDumpConsumerOnUIThread,
+                 weak_factory_.GetWeakPtr(), id));
 }
 
 void RenderProcessHostImpl::RegisterAecDumpConsumerOnUIThread(int id) {
@@ -2535,11 +2490,9 @@
   BrowserThread::PostTaskAndReplyWithResult(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&CreateAecDumpFileForProcess,
-                 file.AddExtension(IntToStringType(id)),
-                 GetHandle()),
+                 file.AddExtension(IntToStringType(id)), GetHandle()),
       base::Bind(&RenderProcessHostImpl::SendAecDumpFileToRenderer,
-                 weak_factory_.GetWeakPtr(),
-                 id));
+                 weak_factory_.GetWeakPtr(), id));
 }
 
 void RenderProcessHostImpl::SendAecDumpFileToRenderer(
@@ -2557,7 +2510,7 @@
 base::FilePath RenderProcessHostImpl::GetAecDumpFilePathWithExtensions(
     const base::FilePath& file) {
   return file.AddExtension(IntToStringType(base::GetProcId(GetHandle())))
-             .AddExtension(kAecDumpFileNameAddition);
+      .AddExtension(kAecDumpFileNameAddition);
 }
 #endif  // defined(ENABLE_WEBRTC)