video_capture_manager: filter out unexpected app state changes on Android

content/browser/renderer_host/media/video_capture_manager.cc

Index: content/browser/renderer_host/media/video_capture_manager.cc
diff --git a/content/browser/renderer_host/media/video_capture_manager.cc b/content/browser/renderer_host/media/video_capture_manager.cc
index b4e9a5c6362f099852b6a5cf9d04f058bc7d3f01..046f6d4439316f4bcfb9fe7ebafb5e09b7836cc4 100644
--- a/content/browser/renderer_host/media/video_capture_manager.cc
+++ b/content/browser/renderer_host/media/video_capture_manager.cc
@@ -252,6 +252,7 @@ void VideoCaptureManager::Register(
   listener_ = listener;
   device_task_runner_ = device_task_runner;
 #if defined(OS_ANDROID)
+  has_stopped_activities = false;
   app_status_listener_.reset(new base::android::ApplicationStatusListener(
       base::Bind(&VideoCaptureManager::OnApplicationStateChange,
                  base::Unretained(this))));
@@ -1081,10 +1082,15 @@ void VideoCaptureManager::OnApplicationStateChange(
     base::android::ApplicationState state) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  if (state == base::android::APPLICATION_STATE_HAS_RUNNING_ACTIVITIES) {
+  // Only release/resume devices when the Application state changes from
+  // RUNNING->STOPPED->RUNNING.
+  if (state == base::android::APPLICATION_STATE_HAS_RUNNING_ACTIVITIES &&
+      has_stopped_activities) {

[perkj_chrome, 2016/06/28 08:59:26]

Suggest rename |has_stopped_activities| to
|application_state_has_running_activities_|  and change the check accordingly. 

     ResumeDevices();
+    has_stopped_activities = false;
   } else if (state == base::android::APPLICATION_STATE_HAS_STOPPED_ACTIVITIES) {
     ReleaseDevices();
+    has_stopped_activities = true;
   }
 }
 
@@ -1105,11 +1111,7 @@ void VideoCaptureManager::ResumeDevices() {
 
   for (auto& entry : devices_) {
     // Do not resume Content Video Capture devices, e.g. Tab or Screen capture.
-    // Do not try to restart already running devices. A device will be running
-    // if the Application state changes from
-    // APPLICATION_STATE_HAS_RUNNING_ACTIVITIES
-    // ->APPLICATION_STATE_HAS_PAUSED_ACTIVITIES
-    // ->APPLICATION_STATE_HAS_RUNNING_ACTIVITIES
+    // Do not try to restart already running devices.
     if (entry->stream_type != MEDIA_DEVICE_VIDEO_CAPTURE ||
         entry->video_capture_device())
       continue;