enable video capture to support sharing across multiple renderer processes

content/browser/renderer_host/media/video_capture_manager.cc

Index: content/browser/renderer_host/media/video_capture_manager.cc
===================================================================
--- content/browser/renderer_host/media/video_capture_manager.cc	(revision 107671)
+++ content/browser/renderer_host/media/video_capture_manager.cc	(working copy)
@@ -5,8 +5,10 @@
 #include "content/browser/renderer_host/media/video_capture_manager.h"
 
 #include "base/bind.h"
-#include "base/memory/scoped_ptr.h"
+#include "base/stl_util.h"
 #include "content/browser/browser_thread.h"
+#include "content/browser/renderer_host/media/video_capture_controller.h"
+#include "content/browser/renderer_host/media/video_capture_controller_event_handler.h"
 #include "media/video/capture/fake_video_capture_device.h"
 #include "media/video/capture/video_capture_device.h"
 
@@ -17,6 +19,21 @@
 // explicitly calling open device.
 enum { kFirstSessionId = VideoCaptureManager::kStartOpenSessionId + 1 };
 
+struct VideoCaptureManager::Controller {
+  Controller(
+      VideoCaptureController* vc_controller,
+      VideoCaptureControllerEventHandler* handler)
+      : controller(vc_controller),
+        ready_to_delete(false) {
+    handlers.push_front(handler);
+  }
+  ~Controller() {}
+
+  scoped_refptr<VideoCaptureController> controller;
+  bool ready_to_delete;
+  Handlers handlers;
+};
+
 VideoCaptureManager::VideoCaptureManager()
   : vc_device_thread_("VideoCaptureManagerThread"),
     listener_(NULL),
@@ -38,6 +55,7 @@
     it->second->DeAllocate();
     delete it->second;
   }
+  STLDeleteValues(&controllers_);
 }
 
 void VideoCaptureManager::Register(MediaStreamProviderListener* listener) {
@@ -193,32 +211,17 @@
   DCHECK(IsOnCaptureDeviceThread());
   DCHECK(video_capture_receiver != NULL);
 
-  // Solution for not using MediaStreamManager.
-  // This session id won't be returned by Open().
-  if (capture_params.session_id == kStartOpenSessionId) {
-    // Start() is called without using Open(), we need to open a device.
-    media::VideoCaptureDevice::Names device_names;
-    GetAvailableDevices(&device_names);
-    if (device_names.empty()) {
-      // No devices available.
-      video_capture_receiver->OnError();
-      return;
-    }
-    StreamDeviceInfo device(kVideoCapture,
-                            device_names.front().device_name,
-                            device_names.front().unique_id, false);
-
-    // Call OnOpen to open using the first device in the list.
-    OnOpen(capture_params.session_id, device);
-  }
-
-  VideoCaptureDevices::iterator it = devices_.find(capture_params.session_id);
-  if (it == devices_.end()) {
+  media::VideoCaptureDevice* video_capture_device =
+      GetDeviceInternal(capture_params.session_id);
+  if (!video_capture_device) {
     // Invalid session id.
     video_capture_receiver->OnError();
     return;
   }
-  media::VideoCaptureDevice* video_capture_device = it->second;
+  Controllers::iterator cit = controllers_.find(video_capture_device);
+  if (cit != controllers_.end()) {
+    cit->second->ready_to_delete = false;
+  }
 
   // Possible errors are signaled to video_capture_receiver by
   // video_capture_device. video_capture_receiver to perform actions.
@@ -240,6 +243,14 @@
     // video_capture_device. video_capture_receiver to perform actions.
     video_capture_device->Stop();
     video_capture_device->DeAllocate();
+    Controllers::iterator cit = controllers_.find(video_capture_device);
+    if (cit != controllers_.end()) {
+      cit->second->ready_to_delete = true;
+      if (cit->second->handlers.size() == 0) {
+        delete cit->second;
+        controllers_.erase(cit);
+      }
+    }
   }
 
   if (!stopped_cb.is_null())
@@ -370,4 +381,106 @@
   return false;
 }
 
+void VideoCaptureManager::AddController(
+    const media::VideoCaptureParams& capture_params,
+    VideoCaptureControllerEventHandler* handler,
+    base::Callback<void(VideoCaptureController*)> added_cb) {
+  DCHECK(handler);
+  vc_device_thread_.message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&VideoCaptureManager::DoAddControllerOnDeviceThread,
+                 base::Unretained(this), capture_params, handler, added_cb));
+}
+
+void VideoCaptureManager::DoAddControllerOnDeviceThread(
+    const media::VideoCaptureParams capture_params,
+    VideoCaptureControllerEventHandler* handler,
+    base::Callback<void(VideoCaptureController*)> added_cb) {
+  DCHECK(IsOnCaptureDeviceThread());
+
+  media::VideoCaptureDevice* video_capture_device =
+      GetDeviceInternal(capture_params.session_id);
+  scoped_refptr<VideoCaptureController> ctrller = NULL;
+  if (video_capture_device) {
+    Controllers::iterator cit = controllers_.find(video_capture_device);
+    if (cit == controllers_.end()) {
+      ctrller = new VideoCaptureController(this);
+      controllers_[video_capture_device] = new Controller(ctrller, handler);
+    } else {
+      controllers_[video_capture_device]->handlers.push_front(handler);
+      ctrller = controllers_[video_capture_device]->controller;
+    }
+  }
+  added_cb.Run(ctrller);
+}
+
+void VideoCaptureManager::RemoveController(
+    VideoCaptureController* controller,
+    VideoCaptureControllerEventHandler* handler) {
+  DCHECK(handler);
+  vc_device_thread_.message_loop()->PostTask(
+      FROM_HERE,
+      base::Bind(&VideoCaptureManager::DoRemoveControllerOnDeviceThread,
+                 base::Unretained(this),
+                 make_scoped_refptr(controller),
+                 handler));
+}
+
+void VideoCaptureManager::DoRemoveControllerOnDeviceThread(
+    VideoCaptureController* controller,
+    VideoCaptureControllerEventHandler* handler) {
+  DCHECK(IsOnCaptureDeviceThread());
+
+  for (Controllers::iterator cit = controllers_.begin();
+       cit != controllers_.end(); ++cit) {
+    if (controller == cit->second->controller) {
+      Handlers& handlers = cit->second->handlers;
+      for (Handlers::iterator hit = handlers.begin();
+           hit != handlers.end(); ++hit) {
+        if ((*hit) == handler) {
+          handlers.erase(hit);
+          break;
+        }
+      }
+      if (handlers.size() == 0 && cit->second->ready_to_delete) {
+        delete cit->second;
+        controllers_.erase(cit);
+      }
+      return;
+    }
+  }
+}
+
+media::VideoCaptureDevice* VideoCaptureManager::GetDeviceInternal(
+    int capture_session_id) {
+  DCHECK(IsOnCaptureDeviceThread());
+  VideoCaptureDevices::iterator dit = devices_.find(capture_session_id);
+  if (dit != devices_.end()) {
+    return dit->second;
+  }
+
+  // Solution for not using MediaStreamManager.
+  // This session id won't be returned by Open().
+  if (capture_session_id == kStartOpenSessionId) {
+    media::VideoCaptureDevice::Names device_names;
+    GetAvailableDevices(&device_names);
+    if (device_names.empty()) {
+      // No devices available.
+      return NULL;
+    }
+    StreamDeviceInfo device(kVideoCapture,
+                            device_names.front().device_name,
+                            device_names.front().unique_id, false);
+
+    // Call OnOpen to open using the first device in the list.
+    OnOpen(capture_session_id, device);
+
+    VideoCaptureDevices::iterator dit = devices_.find(capture_session_id);
+    if (dit != devices_.end()) {
+      return dit->second;
+    }
+  }
+  return NULL;
+}
+
 }  // namespace media_stream