Record whether AudioContext was audible for Autoplay UKM

Implements AudioContextManager mojo interface that can be obtained from a frame so that
audible playback from WebAudio can be recorded by the browser.  Whenever audible playback
starts or stops, a message is sent to the browser indicating such.

Bug: 855069
Change-Id: Ib236a9506a2a6d9b53e95948eb5519145805a2cb
Reviewed-on: https://chromium-review.googlesource.com/1114147
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Hongchan Choi <hongchan@chromium.org>
Commit-Queue: Raymond Toy <rtoy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587867}

content/browser/BUILD.gn

@@ -1171,6 +1171,8 @@ jumbo_source_set("browser") {
     "media/url_provision_fetcher.h",
     "media/video_decoder_proxy.cc",
     "media/video_decoder_proxy.h",
+    "media/webaudio/audio_context_manager_impl.cc",
+    "media/webaudio/audio_context_manager_impl.h",
     "memory/memory_condition_observer.cc",
     "memory/memory_condition_observer.h",
     "memory/memory_coordinator_default_policy.cc",

content/browser/frame_host/interstitial_page_impl.cc

@@ -1090,4 +1090,16 @@ InterstitialPageImpl::GetOrCreateRootBrowserAccessibilityManager() {
   return web_contents_impl->GetOrCreateRootBrowserAccessibilityManager();
 }
 
+void InterstitialPageImpl::AudioContextPlaybackStarted(RenderFrameHost* host,
+                                                       int context_id) {
+  // Interstitial pages should not be playing any sound via WebAudio
+  NOTREACHED();
+}
+
+void InterstitialPageImpl::AudioContextPlaybackStopped(RenderFrameHost* host,
+                                                       int context_id) {
+  // Interstitial pages should not be playing any sound via WebAudio.
+  NOTREACHED();
+}
+
 }  // namespace content

content/browser/frame_host/interstitial_page_impl.h

@@ -138,6 +138,10 @@ class CONTENT_EXPORT InterstitialPageImpl : public InterstitialPage,
                          bool user_gesture) override;
   void SetFocusedFrame(FrameTreeNode* node, SiteInstance* source) override;
   Visibility GetVisibility() const override;
+  void AudioContextPlaybackStarted(RenderFrameHost* host,
+                                   int context_id) override;
+  void AudioContextPlaybackStopped(RenderFrameHost* host,
+                                   int context_id) override;
 
   // RenderViewHostDelegate implementation:
   RenderViewHostDelegateView* GetDelegateView() override;

content/browser/frame_host/render_frame_host_delegate.h

@@ -386,6 +386,13 @@ class CONTENT_EXPORT RenderFrameHostDelegate {
   // Note: This is also exposed by the RenderWidgetHostDelegate.
   virtual ukm::SourceId GetUkmSourceIdForLastCommittedSource() const;
 
+  // Notify observers if WebAudio AudioContext has started (or stopped) playing
+  // audible sounds.
+  virtual void AudioContextPlaybackStarted(RenderFrameHost* host,
+                                           int context_id){};
+  virtual void AudioContextPlaybackStopped(RenderFrameHost* host,
+                                           int context_id){};
+
  protected:
   virtual ~RenderFrameHostDelegate() {}
 };

content/browser/frame_host/render_frame_host_impl.cc

@@ -66,6 +66,7 @@
 #include "content/browser/media/capture/audio_mirroring_manager.h"
 #include "content/browser/media/media_interface_proxy.h"
 #include "content/browser/media/session/media_session_service_impl.h"
+#include "content/browser/media/webaudio/audio_context_manager_impl.h"
 #include "content/browser/payments/payment_app_context_impl.h"
 #include "content/browser/permissions/permission_controller_impl.h"
 #include "content/browser/permissions/permission_service_context.h"
@@ -782,6 +783,14 @@ void RenderFrameHostImpl::DidCommitProvisionalLoadForTesting(
                            std::move(interface_provider_request));
 }
 
+void RenderFrameHostImpl::AudioContextPlaybackStarted(int audio_context_id) {
+  delegate_->AudioContextPlaybackStarted(this, audio_context_id);
+}
+
+void RenderFrameHostImpl::AudioContextPlaybackStopped(int audio_context_id) {
+  delegate_->AudioContextPlaybackStopped(this, audio_context_id);
+}
+
 SiteInstanceImpl* RenderFrameHostImpl::GetSiteInstance() {
   return site_instance_.get();
 }
@@ -3594,6 +3603,9 @@ void RenderFrameHostImpl::RegisterMojoInterfaces() {
 
   registry_->AddInterface(base::BindRepeating(
       &BackgroundFetchServiceImpl::CreateForFrame, GetProcess(), routing_id_));
+
+  registry_->AddInterface(base::BindRepeating(&AudioContextManagerImpl::Create,
+                                              base::Unretained(this)));
 }
 
 void RenderFrameHostImpl::ResetWaitingState() {

content/browser/frame_host/render_frame_host_impl.h

@@ -784,6 +784,11 @@ class CONTENT_EXPORT RenderFrameHostImpl
     return *registry_;
   }
 
+  // Called when the WebAudio AudioContext given by |audio_context_id| has
+  // started (or stopped) playing audible audio.
+  void AudioContextPlaybackStarted(int audio_context_id);
+  void AudioContextPlaybackStopped(int audio_context_id);
+
  protected:
   friend class RenderFrameHostFactory;
 

content/browser/media/webaudio/audio_context_manager_browsertest.cc

@@ -0,0 +1,75 @@
+// Copyright 2018 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 "content/public/browser/web_contents_observer.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/content_browser_test.h"
+#include "content/public/test/content_browser_test_utils.h"
+#include "content/shell/browser/shell.h"
+
+namespace content {
+
+namespace {
+// Test for audible playback message.
+class WaitForAudioContextAudible : WebContentsObserver {
+ public:
+  explicit WaitForAudioContextAudible(WebContents* web_contents)
+      : WebContentsObserver(web_contents) {
+    run_loop_.Run();
+  }
+
+  void AudioContextPlaybackStarted(const AudioContextId&) final {
+    // Stop the run loop when we get the message
+    run_loop_.Quit();
+  }
+
+ private:
+  base::RunLoop run_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaitForAudioContextAudible);
+};
+
+// Test for silent playback started (audible playback stopped).
+class WaitForAudioContextSilent : WebContentsObserver {
+ public:
+  explicit WaitForAudioContextSilent(WebContents* web_contents)
+      : WebContentsObserver(web_contents) {
+    run_loop_.Run();
+  }
+
+  void AudioContextPlaybackStopped(const AudioContextId&) final {
+    // Stop the run loop when we get the message
+    run_loop_.Quit();
+  }
+
+ private:
+  base::RunLoop run_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaitForAudioContextSilent);
+};
+
+}  // namespace
+
+class AudioContextManagerTest : public ContentBrowserTest {};
+
+IN_PROC_BROWSER_TEST_F(AudioContextManagerTest, AudioContextPlaybackRecorded) {
+  NavigateToURL(shell(),
+                content::GetTestUrl("media/webaudio/", "playback-test.html"));
+
+  // Set gain to 1 to start audible audio and verify we got the
+  // playback started message.
+  {
+    ASSERT_TRUE(ExecuteScript(shell()->web_contents(), "gain.gain.value = 1;"));
+    WaitForAudioContextAudible wait(shell()->web_contents());
+  }
+
+  // Set gain to 0 to stop audible audio and verify we got the
+  // playback stopped message.
+  {
+    ASSERT_TRUE(ExecuteScript(shell()->web_contents(), "gain.gain.value = 0;"));
+    WaitForAudioContextSilent wait(shell()->web_contents());
+  }
+}
+
+}  // namespace content

content/browser/media/webaudio/audio_context_manager_impl.cc

@@ -0,0 +1,46 @@
+// Copyright 2018 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 "content/browser/media/webaudio/audio_context_manager_impl.h"
+
+#include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+
+namespace content {
+
+void AudioContextManagerImpl::Create(
+    RenderFrameHost* render_frame_host,
+    blink::mojom::AudioContextManagerRequest request) {
+  mojo::MakeStrongBinding(
+      std::make_unique<AudioContextManagerImpl>(render_frame_host),
+      std::move(request));
+}
+
+AudioContextManagerImpl::AudioContextManagerImpl(
+    RenderFrameHost* render_frame_host)
+    : render_frame_host_impl_(
+          static_cast<RenderFrameHostImpl*>(render_frame_host)) {
+  DCHECK(render_frame_host);
+}
+
+AudioContextManagerImpl::~AudioContextManagerImpl() = default;
+
+void AudioContextManagerImpl::AudioContextAudiblePlaybackStarted(
+    int32_t audio_context_id) {
+  // Notify observers that audible audio started playing from a WebAudio
+  // AudioContext.
+  render_frame_host_impl_->AudioContextPlaybackStarted(audio_context_id);
+}
+
+void AudioContextManagerImpl::AudioContextAudiblePlaybackStopped(
+    int32_t audio_context_id) {
+  // Notify observers that audible audio stopped playing from a WebAudio
+  // AudioContext.
+  render_frame_host_impl_->AudioContextPlaybackStopped(audio_context_id);
+}
+
+}  // namespace content

content/browser/media/webaudio/audio_context_manager_impl.h

@@ -0,0 +1,41 @@
+// Copyright 2018 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.
+
+#ifndef CONTENT_BROWSER_MEDIA_WEBAUDIO_AUDIO_CONTEXT_MANAGER_IMPL_H_
+#define CONTENT_BROWSER_MEDIA_WEBAUDIO_AUDIO_CONTEXT_MANAGER_IMPL_H_
+
+#include "content/common/content_export.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "third_party/blink/public/mojom/webaudio/audio_context_manager.mojom.h"
+
+namespace content {
+
+class RenderFrameHost;
+class RenderFrameHostImpl;
+
+// Implements the mojo interface between WebAudio and the browser so that
+// WebAudio can report when audible sounds from an AudioContext starts and
+// stops.
+class CONTENT_EXPORT AudioContextManagerImpl
+    : public blink::mojom::AudioContextManager {
+ public:
+  explicit AudioContextManagerImpl(RenderFrameHost* render_frame_host);
+  ~AudioContextManagerImpl() override;
+
+  static void Create(RenderFrameHost* render_frame_host,
+                     blink::mojom::AudioContextManagerRequest request);
+
+  // Called when AudioContext starts or stops playing audible audio.
+  void AudioContextAudiblePlaybackStarted(int32_t audio_context_id) final;
+  void AudioContextAudiblePlaybackStopped(int32_t audio_context_id) final;
+
+ private:
+  RenderFrameHostImpl* const render_frame_host_impl_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioContextManagerImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_MEDIA_WEBAUDIO_AUDIO_CONTEXT_MANAGER_IMPL_H_

content/browser/web_contents/web_contents_impl.cc

@@ -6517,6 +6517,20 @@ int WebContentsImpl::GetCurrentlyPlayingVideoCount() {
   return currently_playing_video_count_;
 }
 
+void WebContentsImpl::AudioContextPlaybackStarted(RenderFrameHost* host,
+                                                  int context_id) {
+  WebContentsObserver::AudioContextId audio_context_id(host, context_id);
+  for (auto& observer : observers_)
+    observer.AudioContextPlaybackStarted(audio_context_id);
+}
+
+void WebContentsImpl::AudioContextPlaybackStopped(RenderFrameHost* host,
+                                                  int context_id) {
+  WebContentsObserver::AudioContextId audio_context_id(host, context_id);
+  for (auto& observer : observers_)
+    observer.AudioContextPlaybackStopped(audio_context_id);
+}
+
 void WebContentsImpl::UpdateWebContentsVisibility(Visibility visibility) {
   // Occlusion is disabled when |features::kWebContentsOcclusion| is disabled
   // (for power and speed impact assessment) or when

content/browser/web_contents/web_contents_impl.h

@@ -584,6 +584,14 @@ class CONTENT_EXPORT WebContentsImpl : public WebContents,
       RenderFrameHost* render_frame_host,
       const GlobalRequestID& request_id,
       mojom::ResourceLoadInfoPtr resource_load_information) override;
+
+  // Called when WebAudio starts or stops playing audible audio in an
+  // AudioContext.
+  void AudioContextPlaybackStarted(RenderFrameHost* host,
+                                   int context_id) override;
+  void AudioContextPlaybackStopped(RenderFrameHost* host,
+                                   int context_id) override;
+
   // RenderViewHostDelegate ----------------------------------------------------
   RenderViewHostDelegateView* GetDelegateView() override;
   bool OnMessageReceived(RenderViewHostImpl* render_view_host,

content/public/app/mojo/content_browser_manifest.json

@@ -151,6 +151,7 @@
           "autofill.mojom.AutofillDriver",
           "autofill.mojom.PasswordManagerDriver",
           "blink.mojom.AnchorElementMetricsHost",
+          "blink.mojom.AudioContextManager",
           "blink.mojom.Authenticator",
           "blink.mojom.BackgroundFetchService",
           "blink.mojom.CacheStorage",

content/public/browser/web_contents_observer.h

@@ -542,6 +542,13 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener {
   // tab.
   virtual void DidCommitAndDrawCompositorFrame() {}
 
+  // Called when "audible" playback starts or stops on a WebAudio AudioContext.
+  using AudioContextId = std::pair<RenderFrameHost*, int>;
+  virtual void AudioContextPlaybackStarted(
+      const AudioContextId& audio_context_id) {}
+  virtual void AudioContextPlaybackStopped(
+      const AudioContextId& audio_context_id) {}
+
   // IPC::Listener implementation.
   // DEPRECATED: Use (i.e. override) the other overload instead:
   //     virtual bool OnMessageReceived(const IPC::Message& message,

content/test/BUILD.gn

@@ -802,6 +802,7 @@ test("content_browsertests") {
     "../browser/media/session/media_session_service_impl_browsertest.cc",
     "../browser/media/session/mock_media_session_player_observer.cc",
     "../browser/media/session/mock_media_session_player_observer.h",
+    "../browser/media/webaudio/audio_context_manager_browsertest.cc",
     "../browser/memory/memory_coordinator_impl_browsertest.cc",
     "../browser/message_port_provider_browsertest.cc",
     "../browser/mojo_sandbox_browsertest.cc",

content/test/data/media/webaudio/playback-test.html

@@ -0,0 +1,21 @@
+<!doctype html>
+<html>
+  <head>
+    <title>Test AudioContextManager Audible Playback</title>
+  </head>
+
+  <body>
+    <script>
+      let context = new AudioContext();
+      let osc = new OscillatorNode(context);
+      // Set initial gain to 0 to make sure we start with silence.
+      let gain = new GainNode(context, {gain: 0});
+
+      // Connect everything and start the oscillator.  The browser test will set the gain value as
+      // needed to test if the messages are being sent.
+      osc.connect(gain).connect(context.destination);
+      osc.start();
+
+    </script>
+  </body>
+</html>

third_party/blink/public/mojom/BUILD.gn

@@ -62,6 +62,7 @@ mojom("mojom_platform") {
     "speech/speech_recognizer.mojom",
     "use_counter/css_property_id.mojom",
     "web_package/web_package_internals.mojom",
+    "webaudio/audio_context_manager.mojom",
   ]
 
   public_deps = [

third_party/blink/public/mojom/webaudio/OWNERS

@@ -0,0 +1,6 @@
+file://third_party/blink/renderer/modules/webaudio/OWNERS
+
+# COMPONENT: Blink>WebAudio
+
+per-file *.mojom=set noparent
+per-file *.mojom=file://ipc/SECURITY_OWNERS

third_party/blink/public/mojom/webaudio/audio_context_manager.mojom

@@ -0,0 +1,19 @@
+// Copyright 2018 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.
+
+module blink.mojom;
+
+// Interface for allowing a real-time AudioContext to send
+// notifications to browser that the AudioContext has started (or
+// stopped) playing audible sounds.  Audibility is computed by the
+// AudioContext.
+interface AudioContextManager {
+  // AudioContext started producing audible sound.  The id is the ID
+  // of the AudioContext.
+  AudioContextAudiblePlaybackStarted(int32 id);
+
+  // AudioContext stopped producing audible sound.  The id is the ID
+  // of the AudioContext.
+  AudioContextAudiblePlaybackStopped(int32 id);
+};