Use AudioStreamMonitor to control power save blocking.

content/browser/media/audio_stream_monitor.cc

Index: content/browser/media/audio_stream_monitor.cc
diff --git a/chrome/browser/media/audio_stream_monitor.cc b/content/browser/media/audio_stream_monitor.cc
similarity index 42%
rename from chrome/browser/media/audio_stream_monitor.cc
rename to content/browser/media/audio_stream_monitor.cc
index 8633053d510684d1a69143590ec9d3047eb44194..7b13bc4adceb2b9462a9700841c51e193e9bbf7a 100644
--- a/chrome/browser/media/audio_stream_monitor.cc
+++ b/content/browser/media/audio_stream_monitor.cc
@@ -2,14 +2,49 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/media/audio_stream_monitor.h"
+#include "content/browser/media/audio_stream_monitor.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/invalidate_type.h"
+#include "content/public/browser/power_save_blocker.h"
+#include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 
-DEFINE_WEB_CONTENTS_USER_DATA_KEY(AudioStreamMonitor);
+namespace content {
+
+namespace {
+
+AudioStreamMonitor* AudioStreamMonitorFromRenderFrame(int render_process_id,
+                                                      int render_frame_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  content::WebContents* const web_contents =

[jam, 2014/09/02 19:50:33]

nit: remove content:: from this file

[DaleCurtis, 2014/09/04 21:59:06]

Done.

+      content::WebContents::FromRenderFrameHost(
+          content::RenderFrameHost::FromID(render_process_id, render_frame_id));
+  if (!web_contents)
+    return NULL;
+
+  // Note: Calling CreateForWebContents() multiple times is valid (see usage
+  // info for content::WebContentsUserData).
+  AudioStreamMonitor::CreateForWebContents(web_contents);
+  return AudioStreamMonitor::FromWebContents(web_contents);
+}
+
+}  // namespace
+
+// TODO(dalecurtis): ???? DEFINE_WEB_CONTENTS_USER_DATA_KEY won't link,

[DaleCurtis, 2014/09/03 18:48:55]

No ideas on what's going on here? :)

[miu, 2014/09/03 22:41:53]

If you were compiling on Windows, I would suggest:

class CONTENT_EXPORT AudioStreamMonitor
    : NON_EXPORTED_BASE(public WebContentsUserData<AudioStreamMonitor>) {
      ^^^^^^^^^^^^^^^^^

But on posix, I'm not sure.  Is it when you link chrome or content_unittests?

[DaleCurtis, 2014/09/04 21:59:06]

Correct. I tried NON_EXPORTED_BASE before creating what you see below, no luck
:|

+// kLocatorKey is created as a local symbol without the CONTENT_EXPORT
+// addition... without it, nm shows:
+//
+// $ nm content_unittests.audio_stream_monitor_unittest.o | grep kLocatorKey
+//                    U _ZN7content19...AudioStreamMonitorEE11kLocatorKeyE
+// $ nm libcontent.so | grep AudioStreamMonitor | grep kLocatorkey
+//   000000000139d8f0 b _ZN7content19...AudioStreamMonitorEE11kLocatorKeyE
+//
+template <>
+CONTENT_EXPORT int
+    content::WebContentsUserData<AudioStreamMonitor>::kLocatorKey = 0;
 
 AudioStreamMonitor::AudioStreamMonitor(content::WebContents* contents)
     : web_contents_(contents),
@@ -25,7 +60,58 @@ bool AudioStreamMonitor::WasRecentlyAudible() const {
   return was_recently_audible_;
 }
 
+/* static */
 void AudioStreamMonitor::StartMonitoringStream(
+    int render_process_id,
+    int render_frame_id,
+    int stream_id,
+    const ReadPowerAndClipCallback& read_power_callback) {
+  BrowserThread::PostTask(BrowserThread::UI,
+                          FROM_HERE,
+                          base::Bind(&StartMonitoringHelper,
+                                     render_process_id,
+                                     render_frame_id,
+                                     stream_id,
+                                     read_power_callback));
+}
+
+/* static */
+void AudioStreamMonitor::StopMonitoringStream(int render_process_id,
+                                              int render_frame_id,
+                                              int stream_id) {
+  BrowserThread::PostTask(BrowserThread::UI,
+                          FROM_HERE,
+                          base::Bind(&StopMonitoringHelper,
+                                     render_process_id,
+                                     render_frame_id,
+                                     stream_id));
+}
+
+/* static */
+void AudioStreamMonitor::StartMonitoringHelper(
+    int render_process_id,
+    int render_frame_id,
+    int stream_id,
+    const ReadPowerAndClipCallback& read_power_callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  AudioStreamMonitor* const monitor =
+      AudioStreamMonitorFromRenderFrame(render_process_id, render_frame_id);
+  if (monitor)
+    monitor->StartMonitoringStreamOnUIThread(stream_id, read_power_callback);
+}
+
+/* static */
+void AudioStreamMonitor::StopMonitoringHelper(int render_process_id,
+                                              int render_frame_id,
+                                              int stream_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  AudioStreamMonitor* const monitor =
+      AudioStreamMonitorFromRenderFrame(render_process_id, render_frame_id);
+  if (monitor)
+    monitor->StopMonitoringStreamOnUIThread(stream_id);
+}
+
+void AudioStreamMonitor::StartMonitoringStreamOnUIThread(
     int stream_id,
     const ReadPowerAndClipCallback& read_power_callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
@@ -39,7 +125,7 @@ void AudioStreamMonitor::StartMonitoringStream(
   }
 }
 
-void AudioStreamMonitor::StopMonitoringStream(int stream_id) {
+void AudioStreamMonitor::StopMonitoringStreamOnUIThread(int stream_id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   poll_callbacks_.erase(stream_id);
   if (poll_callbacks_.empty())
@@ -77,10 +163,18 @@ void AudioStreamMonitor::MaybeToggle() {
 
   if (!should_indicator_be_on) {
     off_timer_.Stop();
+    blocker_.reset();
   } else if (!off_timer_.IsRunning()) {
+    if (!blocker_) {
+      blocker_ = content::PowerSaveBlocker::Create(

[miu, 2014/09/02 21:04:39]

Can we move this into WebContentsImpl now?  Meaning, in
WebContentsImpl::NotifyNavigationStateChanged(), add something like:

  if (WasRecentlyAudible()) {
    // Make sure WebContentsImpl::power_save_blocker_ is instantiated.
  } else {
    // Make sure there is no power_save_blocker_ unless there is video playing.
  }

[DaleCurtis, 2014/09/03 18:48:55]

Let me play with it. I think that's a great idea if it works out.

[DaleCurtis, 2014/09/04 21:59:06]

Done.

+          content::PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension,
+          "Playing Audio");
+    }
     off_timer_.Start(
         FROM_HERE,
         off_time - now,
         base::Bind(&AudioStreamMonitor::MaybeToggle, base::Unretained(this)));
   }
 }
+
+}  // namespace content