Video Capture: Allow suspension of individual devices.

content/browser/renderer_host/media/video_capture_manager.cc

 // Copyright (c) 2012 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/renderer_host/media/video_capture_manager.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 
@@ skipping 721 matching lines @@
     VideoCaptureController* controller,
     VideoCaptureControllerID client_id,
     VideoCaptureControllerEventHandler* client_handler) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(controller);
   DCHECK(client_handler);
   DeviceEntry* entry = GetDeviceEntryByController(controller);
   if (!entry)
     NOTREACHED() << "Got Null entry while pausing capture";
 
-  // Do not pause Content Video Capture devices, e.g. Tab or Screen capture.
-  if (entry->stream_type != MEDIA_DEVICE_VIDEO_CAPTURE)
+  const bool had_active_client = controller->HasActiveClient();
+  controller->PauseClient(client_id, client_handler);
+  if (!had_active_client || controller->HasActiveClient())
     return;
-
-  controller->PauseClient(client_id, client_handler);
+  if (media::VideoCaptureDevice* device = entry->video_capture_device()) {
+    device_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&VideoCaptureDevice::MaybeSuspend,
+                   // Unretained is safe to use here because |device| would be
+                   // null if it was scheduled for shutdown and destruction, and
+                   // because this task is guaranteed to run before the task
+                   // that destroys the |device|.
+                   base::Unretained(device)));
+  }
 }
 
 void VideoCaptureManager::ResumeCaptureForClient(
     media::VideoCaptureSessionId session_id,
     const media::VideoCaptureParams& params,
     VideoCaptureController* controller,
     VideoCaptureControllerID client_id,
     VideoCaptureControllerEventHandler* client_handler) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(controller);
   DCHECK(client_handler);
 
   DeviceEntry* entry = GetDeviceEntryByController(controller);
   if (!entry)
     NOTREACHED() << "Got Null entry while resuming capture";
 
-  // Do not resume Content Video Capture devices, e.g. Tab or Screen capture.
-  if (entry->stream_type != MEDIA_DEVICE_VIDEO_CAPTURE)
+  const bool had_active_client = controller->HasActiveClient();
+  controller->ResumeClient(client_id, client_handler);
+  if (had_active_client || !controller->HasActiveClient())
     return;
-
-  controller->ResumeClient(client_id, client_handler);
+  if (media::VideoCaptureDevice* device = entry->video_capture_device()) {
+    device_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&VideoCaptureDevice::Resume,
+                   // Unretained is safe to use here because |device| would be
+                   // null if it was scheduled for shutdown and destruction, and
+                   // because this task is guaranteed to run before the task
+                   // that destroys the |device|.
+                   base::Unretained(device)));
+  }
 }
 
 void VideoCaptureManager::RequestRefreshFrameForClient(
     VideoCaptureController* controller) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   if (DeviceEntry* entry = GetDeviceEntryByController(controller)) {
     if (media::VideoCaptureDevice* device = entry->video_capture_device()) {
       device_task_runner_->PostTask(
           FROM_HERE,
@@ skipping 486 matching lines @@
     if (!device_in_queue) {
       // Session ID is only valid for Screen capture. So we can fake it to
       // resume video capture devices here.
       QueueStartDevice(kFakeSessionId, entry.get(), entry->parameters);
     }
   }
 }
 #endif  // defined(OS_ANDROID)
 
 }  // namespace content