WebAudio: do not use a fake audio device during layout tests.

This CL removes ContentRendererClient::OverrideCreateAudioDevice because
it breaks Web Audio tests that rely on rendering. Indeed, the fake audio
path used for layout tests wouldn't notify the audio destination node
that playback happened which means that calls to `resume()` would never
be resolved as they are dependant on the audio context to start
rendering.

This code was added a 5 years ago and the CL does not explain why nor
link to a bug:
https://chromium.googlesource.com/chromium/src/+/f065ec59efdaa8e00940381a99b93ef7960ba0f5%5E%21/

Bug: None
Change-Id: Ifc6854f97bdaf580b24cfc28460153b243188ac2
Reviewed-on: https://chromium-review.googlesource.com/1067100
Commit-Queue: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Raymond Toy <rtoy@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560909}

content/public/renderer/content_renderer_client.cc

@@ -64,12 +64,6 @@ ContentRendererClient::OverrideCreateMIDIAccessor(
   return nullptr;
 }
 
-std::unique_ptr<blink::WebAudioDevice>
-ContentRendererClient::OverrideCreateAudioDevice(
-    const blink::WebAudioLatencyHint& latency_hint) {
-  return nullptr;
-}
-
 blink::WebThemeEngine* ContentRendererClient::OverrideThemeEngine() {
   return nullptr;
 }

content/public/renderer/content_renderer_client.h

@@ -39,8 +39,6 @@ class SingleThreadTaskRunner;
 }
 
 namespace blink {
-class WebAudioDevice;
-class WebAudioLatencyHint;
 class WebFrame;
 class WebLocalFrame;
 class WebMIDIAccessor;
@@ -166,11 +164,6 @@ class CONTENT_EXPORT ContentRendererClient {
   virtual std::unique_ptr<blink::WebMIDIAccessor> OverrideCreateMIDIAccessor(
       blink::WebMIDIAccessorClient* client);
 
-  // Allows the embedder to override creating a WebAudioDevice.  If it
-  // returns NULL the content layer will create the audio device.
-  virtual std::unique_ptr<blink::WebAudioDevice> OverrideCreateAudioDevice(
-      const blink::WebAudioLatencyHint& latency_hint);
-
   // Allows the embedder to override the WebThemeEngine used. If it returns NULL
   // the content layer will provide an engine.
   virtual blink::WebThemeEngine* OverrideThemeEngine();

content/renderer/renderer_blink_platform_impl.cc

@@ -727,12 +727,6 @@ std::unique_ptr<WebAudioDevice> RendererBlinkPlatformImpl::CreateAudioDevice(
     const blink::WebAudioLatencyHint& latency_hint,
     WebAudioDevice::RenderCallback* callback,
     const blink::WebString& input_device_id) {
-  // Use a mock for testing.
-  std::unique_ptr<blink::WebAudioDevice> mock_device =
-      GetContentClient()->renderer()->OverrideCreateAudioDevice(latency_hint);
-  if (mock_device)
-    return mock_device;
-
   // The |channels| does not exactly identify the channel layout of the
   // device. The switch statement below assigns a best guess to the channel
   // layout based on number of channels.

content/shell/renderer/layout_test/layout_test_content_renderer_client.cc

@@ -170,39 +170,6 @@ LayoutTestContentRendererClient::OverrideCreateMIDIAccessor(
   return interfaces->CreateMIDIAccessor(client);
 }
 
-std::unique_ptr<WebAudioDevice>
-LayoutTestContentRendererClient::OverrideCreateAudioDevice(
-    const blink::WebAudioLatencyHint& latency_hint) {
-  const double hw_buffer_size = 128;
-  const double hw_sample_rate = 44100;
-  double buffer_size = 0;
-  switch (latency_hint.Category()) {
-    case blink::WebAudioLatencyHint::kCategoryInteractive:
-      buffer_size =
-          media::AudioLatency::GetInteractiveBufferSize(hw_buffer_size);
-      break;
-    case blink::WebAudioLatencyHint::kCategoryBalanced:
-      buffer_size =
-          media::AudioLatency::GetRtcBufferSize(hw_sample_rate, hw_buffer_size);
-      break;
-    case blink::WebAudioLatencyHint::kCategoryPlayback:
-      buffer_size = media::AudioLatency::GetHighLatencyBufferSize(
-          hw_sample_rate, hw_buffer_size);
-      break;
-    case blink::WebAudioLatencyHint::kCategoryExact:
-      buffer_size = media::AudioLatency::GetExactBufferSize(
-          base::TimeDelta::FromSecondsD(latency_hint.Seconds()), hw_sample_rate,
-          hw_buffer_size);
-      break;
-    default:
-      NOTREACHED();
-      break;
-  }
-  test_runner::WebTestInterfaces* interfaces =
-      LayoutTestRenderThreadObserver::GetInstance()->test_interfaces();
-  return interfaces->CreateAudioDevice(hw_sample_rate, buffer_size);
-}
-
 WebThemeEngine* LayoutTestContentRendererClient::OverrideThemeEngine() {
   return LayoutTestRenderThreadObserver::GetInstance()
       ->test_interfaces()

content/shell/renderer/layout_test/layout_test_content_renderer_client.h

@@ -24,8 +24,6 @@ class LayoutTestContentRendererClient : public ShellContentRendererClient {
   void RenderViewCreated(RenderView* render_view) override;
   std::unique_ptr<blink::WebMIDIAccessor> OverrideCreateMIDIAccessor(
       blink::WebMIDIAccessorClient* client) override;
-  std::unique_ptr<blink::WebAudioDevice> OverrideCreateAudioDevice(
-      const blink::WebAudioLatencyHint& latency_hint) override;
   blink::WebThemeEngine* OverrideThemeEngine() override;
   std::unique_ptr<MediaStreamRendererFactory> CreateMediaStreamRendererFactory()
       override;

content/shell/test_runner/BUILD.gn

@@ -38,8 +38,6 @@ component("test_runner") {
     "mock_screen_orientation_client.h",
     "mock_spell_check.cc",
     "mock_spell_check.h",
-    "mock_web_audio_device.cc",
-    "mock_web_audio_device.h",
     "mock_web_document_subresource_filter.cc",
     "mock_web_document_subresource_filter.h",
     "mock_web_midi_accessor.cc",

content/shell/test_runner/mock_web_audio_device.cc

-// Copyright 2014 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/shell/test_runner/mock_web_audio_device.h"
-
-namespace test_runner {
-
-MockWebAudioDevice::MockWebAudioDevice(double sample_rate,
-                                       int frames_per_buffer)
-    : sample_rate_(sample_rate), frames_per_buffer_(frames_per_buffer) {}
-
-MockWebAudioDevice::~MockWebAudioDevice() {}
-
-void MockWebAudioDevice::Start() {}
-
-void MockWebAudioDevice::Stop() {}
-
-double MockWebAudioDevice::SampleRate() {
-  return sample_rate_;
-}
-
-int MockWebAudioDevice::FramesPerBuffer() {
-  return frames_per_buffer_;
-}
-
-}  // namespace test_runner

content/shell/test_runner/mock_web_audio_device.h

-// Copyright 2014 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_SHELL_TEST_RUNNER_MOCK_WEB_AUDIO_DEVICE_H_
-#define CONTENT_SHELL_TEST_RUNNER_MOCK_WEB_AUDIO_DEVICE_H_
-
-#include "base/macros.h"
-#include "third_party/blink/public/platform/web_audio_device.h"
-
-namespace test_runner {
-
-class MockWebAudioDevice : public blink::WebAudioDevice {
- public:
-  explicit MockWebAudioDevice(double sample_rate, int frames_per_buffer);
-  ~MockWebAudioDevice() override;
-
-  // blink::WebAudioDevice:
-  void Start() override;
-  void Stop() override;
-  double SampleRate() override;
-  int FramesPerBuffer() override;
-
- private:
-  double sample_rate_;
-  int frames_per_buffer_;
-
-  DISALLOW_COPY_AND_ASSIGN(MockWebAudioDevice);
-};
-
-}  // namespace test_runner
-
-#endif  // CONTENT_SHELL_TEST_RUNNER_MOCK_WEB_AUDIO_DEVICE_H_

content/shell/test_runner/web_test_interfaces.cc

@@ -6,7 +6,6 @@
 
 #include <utility>
 
-#include "content/shell/test_runner/mock_web_audio_device.h"
 #include "content/shell/test_runner/mock_web_midi_accessor.h"
 #include "content/shell/test_runner/test_interfaces.h"
 #include "content/shell/test_runner/test_runner.h"
@@ -69,12 +68,6 @@ std::unique_ptr<WebMIDIAccessor> WebTestInterfaces::CreateMIDIAccessor(
   return std::make_unique<MockWebMIDIAccessor>(client, interfaces_.get());
 }
 
-std::unique_ptr<WebAudioDevice> WebTestInterfaces::CreateAudioDevice(
-    double sample_rate,
-    int frames_per_buffer) {
-  return std::make_unique<MockWebAudioDevice>(sample_rate, frames_per_buffer);
-}
-
 std::unique_ptr<WebFrameTestClient> WebTestInterfaces::CreateWebFrameTestClient(
     WebViewTestProxyBase* web_view_test_proxy_base,
     WebFrameTestProxyBase* web_frame_test_proxy_base) {

content/shell/test_runner/web_test_interfaces.h

@@ -12,7 +12,6 @@
 #include "content/shell/test_runner/test_runner_export.h"
 
 namespace blink {
-class WebAudioDevice;
 class WebFrameClient;
 class WebMIDIAccessor;
 class WebMIDIAccessorClient;
@@ -67,10 +66,6 @@ class TEST_RUNNER_EXPORT WebTestInterfaces {
   std::unique_ptr<blink::WebMIDIAccessor> CreateMIDIAccessor(
       blink::WebMIDIAccessorClient* client);
 
-  std::unique_ptr<blink::WebAudioDevice> CreateAudioDevice(
-      double sample_rate,
-      int frames_per_buffer);
-
   TestInterfaces* GetTestInterfaces();
 
   // Creates a WebFrameClient implementation providing test behavior (i.e.