Use rtc::scoped_refptr for WebRtcVideoCapturer.

Un-breaks peerconnection_client which would instantly use-after-free on
an allocated VCM because it wasn't building a scoped_refptr so all
references to the VCM were dropped.

BUG=webrtc:5229
TBR=tommi@webrtc.org
TEST=Run peerconnection_client locally, verify that there's no crash.

Review URL: https://codereview.webrtc.org/1817953005 .

Cr-Commit-Position: refs/heads/master@{#12088}

webrtc/media/engine/fakewebrtcvcmfactory.h

@@ -21,11 +21,13 @@
 // WebRtcVideoCapturer.
 class FakeWebRtcVcmFactory : public cricket::WebRtcVcmFactoryInterface {
  public:
-  virtual webrtc::VideoCaptureModule* Create(int module_id,
-                                             const char* device_id) {
+  virtual rtc::scoped_refptr<webrtc::VideoCaptureModule> Create(
+      int module_id,
+      const char* device_id) {
     if (!device_info.GetDeviceById(device_id)) return NULL;
-    FakeWebRtcVideoCaptureModule* module =
-        new FakeWebRtcVideoCaptureModule(this, module_id);
+    rtc::scoped_refptr<FakeWebRtcVideoCaptureModule> module(
+        new rtc::RefCountedObject<FakeWebRtcVideoCaptureModule>(this,
+                                                                module_id));
     modules.push_back(module);
     return module;
   }
@@ -38,7 +40,7 @@ class FakeWebRtcVcmFactory : public cricket::WebRtcVcmFactoryInterface {
     std::remove(modules.begin(), modules.end(), module);
   }
   FakeWebRtcDeviceInfo device_info;
-  std::vector<FakeWebRtcVideoCaptureModule*> modules;
+  std::vector<rtc::scoped_refptr<FakeWebRtcVideoCaptureModule>> modules;
 };
 
 FakeWebRtcVideoCaptureModule::~FakeWebRtcVideoCaptureModule() {

webrtc/media/engine/fakewebrtcvideocapturemodule.h

@@ -28,6 +28,7 @@ class FakeWebRtcVideoCaptureModule : public webrtc::VideoCaptureModule {
         running_(false),
         delay_(0) {
   }
+  ~FakeWebRtcVideoCaptureModule();
   int64_t TimeUntilNextProcess() override { return 0; }
   void Process() override {}
   void RegisterCaptureDataCallback(
@@ -83,11 +84,6 @@ class FakeWebRtcVideoCaptureModule : public webrtc::VideoCaptureModule {
       const webrtc::VideoCodec& codec) override {
     return NULL;  // not implemented
   }
-  int32_t AddRef() const override { return 0; }
-  int32_t Release() const override {
-    delete this;
-    return 0;
-  }
 
   void SendFrame(int w, int h) {
     if (!running_) return;
@@ -104,9 +100,6 @@ class FakeWebRtcVideoCaptureModule : public webrtc::VideoCaptureModule {
   }
 
  private:
-  // Ref-counted, use Release() instead.
-  ~FakeWebRtcVideoCaptureModule();
-
   FakeWebRtcVcmFactory* factory_;
   int id_;
   webrtc::VideoCaptureDataCallback* callback_;

webrtc/media/engine/webrtcvideocapturer.cc

@@ -52,7 +52,9 @@ static kVideoFourCCEntry kSupportedFourCCs[] = {
 
 class WebRtcVcmFactory : public WebRtcVcmFactoryInterface {
  public:
-  virtual webrtc::VideoCaptureModule* Create(int id, const char* device) {
+  virtual rtc::scoped_refptr<webrtc::VideoCaptureModule> Create(
+      int id,
+      const char* device) {
     return webrtc::VideoCaptureFactory::Create(id, device);
   }
   virtual webrtc::VideoCaptureModule::DeviceInfo* CreateDeviceInfo(int id) {
@@ -128,11 +130,7 @@ WebRtcVideoCapturer::WebRtcVideoCapturer(WebRtcVcmFactoryInterface* factory)
   set_frame_factory(new WebRtcVideoFrameFactory());
 }
 
-WebRtcVideoCapturer::~WebRtcVideoCapturer() {
-  if (module_) {
-    module_->Release();
-  }
-}
+WebRtcVideoCapturer::~WebRtcVideoCapturer() {}
 
 bool WebRtcVideoCapturer::Init(const Device& device) {
   RTC_DCHECK(!start_thread_);
@@ -198,14 +196,14 @@ bool WebRtcVideoCapturer::Init(const Device& device) {
   }
 
   // It is safe to change member attributes now.
-  module_->AddRef();
   SetId(device.id);
   SetSupportedFormats(supported);
 
   return true;
 }
 
-bool WebRtcVideoCapturer::Init(webrtc::VideoCaptureModule* module) {
+bool WebRtcVideoCapturer::Init(
+    const rtc::scoped_refptr<webrtc::VideoCaptureModule>& module) {
   RTC_DCHECK(!start_thread_);
   if (module_) {
     LOG(LS_ERROR) << "The capturer is already initialized";
@@ -216,7 +214,7 @@ bool WebRtcVideoCapturer::Init(webrtc::VideoCaptureModule* module) {
     return false;
   }
   // TODO(juberti): Set id and formats.
-  (module_ = module)->AddRef();
+  module_ = module;
   return true;
 }
 

webrtc/media/engine/webrtcvideocapturer.h

@@ -17,6 +17,7 @@
 
 #include "webrtc/base/asyncinvoker.h"
 #include "webrtc/base/messagehandler.h"
+#include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/media/base/device.h"
 #include "webrtc/media/base/videocapturer.h"
@@ -30,8 +31,9 @@ namespace cricket {
 class WebRtcVcmFactoryInterface {
  public:
   virtual ~WebRtcVcmFactoryInterface() {}
-  virtual webrtc::VideoCaptureModule* Create(
-      int id, const char* device) = 0;
+  virtual rtc::scoped_refptr<webrtc::VideoCaptureModule> Create(
+      int id,
+      const char* device) = 0;
   virtual webrtc::VideoCaptureModule::DeviceInfo* CreateDeviceInfo(int id) = 0;
   virtual void DestroyDeviceInfo(
       webrtc::VideoCaptureModule::DeviceInfo* info) = 0;
@@ -46,7 +48,7 @@ class WebRtcVideoCapturer : public VideoCapturer,
   virtual ~WebRtcVideoCapturer();
 
   bool Init(const Device& device);
-  bool Init(webrtc::VideoCaptureModule* module);
+  bool Init(const rtc::scoped_refptr<webrtc::VideoCaptureModule>& module);
 
   // Override virtual methods of the parent class VideoCapturer.
   bool GetBestCaptureFormat(const VideoFormat& desired,
@@ -77,7 +79,7 @@ class WebRtcVideoCapturer : public VideoCapturer,
   void SignalFrameCapturedOnStartThread(const webrtc::VideoFrame& frame);
 
   std::unique_ptr<WebRtcVcmFactoryInterface> factory_;
-  webrtc::VideoCaptureModule* module_;
+  rtc::scoped_refptr<webrtc::VideoCaptureModule> module_;
   int captured_frames_;
   std::vector<uint8_t> capture_buffer_;
   rtc::Thread* start_thread_;  // Set in Start(), unset in Stop();