Added video capture capabilities retrieval and caching to VideoCaptureManager

media/video/capture/fake_video_capture_device.cc

Index: media/video/capture/fake_video_capture_device.cc
diff --git a/media/video/capture/fake_video_capture_device.cc b/media/video/capture/fake_video_capture_device.cc
index 278bfcb284958899b792ba3da95d73d556c85117..966d6a9289df6bf5b05d6ec7696e747dfd4dcc9d 100644
--- a/media/video/capture/fake_video_capture_device.cc
+++ b/media/video/capture/fake_video_capture_device.cc
@@ -37,12 +37,19 @@ void FakeVideoCaptureDevice::GetDeviceNames(Names* const device_names) {
 void FakeVideoCaptureDevice::GetDeviceSupportedFormats(
     const Name& device,
     VideoCaptureCapabilities* formats) {
-  VideoCaptureCapability capture_format;
-  capture_format.color = media::PIXEL_FORMAT_I420;
-  capture_format.width = 640;
-  capture_format.height = 480;
-  capture_format.frame_rate = 1000 / kFakeCaptureTimeoutMs;
-  formats->push_back(capture_format);
+  formats->clear();
+  VideoCaptureCapability capture_format_640x480;
+  capture_format_640x480.color = media::PIXEL_FORMAT_I420;
+  capture_format_640x480.width = 640;
+  capture_format_640x480.height = 480;
+  capture_format_640x480.frame_rate = 1000 / kFakeCaptureTimeoutMs;
+  formats->push_back(capture_format_640x480);
+  VideoCaptureCapability capture_format_320x240;
+  capture_format_320x240.color = media::PIXEL_FORMAT_I420;
+  capture_format_320x240.width = 320;
+  capture_format_320x240.height = 240;
+  capture_format_320x240.frame_rate = 1000 / kFakeCaptureTimeoutMs;
+  formats->push_back(capture_format_320x240);
 }
 
 VideoCaptureDevice* FakeVideoCaptureDevice::Create(const Name& device_name) {