Hook up EncodedVideoSource on the browser side

media/video/capture/mac/video_capture_device_mac.mm

Index: media/video/capture/mac/video_capture_device_mac.mm
diff --git a/media/video/capture/mac/video_capture_device_mac.mm b/media/video/capture/mac/video_capture_device_mac.mm
index f18eb540bcef59bda8191769f99506978516edc4..c85b596e4730436c94a16450476e1ff67fe6565d 100644
--- a/media/video/capture/mac/video_capture_device_mac.mm
+++ b/media/video/capture/mac/video_capture_device_mac.mm
@@ -85,6 +85,14 @@ VideoCaptureDeviceMac::~VideoCaptureDeviceMac() {
   [capture_device_ release];
 }
 
+VideoEncodingCapability VideoCaptureDeviceMac::GetEncodingCapability() {
+  return VideoEncodingCapability();
+}
+
+void VideoCaptureDeviceMac::TryConfigureEncodedBitstream(
+    const RuntimeVideoEncodingParameters& params) {
+}
+
 void VideoCaptureDeviceMac::Allocate(int width, int height, int frame_rate,
                                      EventHandler* observer) {
   if (state_ != kIdle) {