Add VideoCaptureDevice::GetDeviceSupportedFormats to interface + implementation for Linux and Fake

media/video/capture/video_capture_device.h

Index: media/video/capture/video_capture_device.h
diff --git a/media/video/capture/video_capture_device.h b/media/video/capture/video_capture_device.h
index e7340841ceecf5a22212489d86d449f672a76a39..bd767485f7aae1a61855957402ec157e22fe5890 100644
--- a/media/video/capture/video_capture_device.h
+++ b/media/video/capture/video_capture_device.h
@@ -181,6 +181,11 @@ class MEDIA_EXPORT VideoCaptureDevice {
     // Called when the native resolution of VideoCaptureDevice has been changed
     // and it needs to inform its client of the new frame size.
     virtual void OnFrameInfoChanged(const VideoCaptureCapability& info) {};
+
+    // Called when VideoCaptureDevice::GetDeviceSupportedFormats() has been
+    // called, to reply with the the resulting device capabilities.
+    virtual void OnDeviceSupportedFormatsEnumerated(
+        const VideoCaptureFormats& formats) {};
   };
   // Creates a VideoCaptureDevice object.
   // Return NULL if the hardware is not available.
@@ -210,6 +215,13 @@ class MEDIA_EXPORT VideoCaptureDevice {
   // would be sequenced through the same task runner, so that deallocation
   // happens first.
   virtual void StopAndDeAllocate() = 0;
+
+  // Gets the supported video capture formats, if operation is supported by the
+  // driver, for a particular video capture device. This operation may be called
+  // before or after AllocateAndStart, and it may take into account the current
+  // state of the device, f.i. an already opened device might see supported
+  // formats limited etc.
+  virtual void GetDeviceSupportedFormats(scoped_ptr<EventHandler> client) {};

[perkj_chrome, 2013/09/25 07:58:41]

Instead of |client| beeing an EventHandler - it might be easier to just let it
be of type base::CallBack, see MediaRequestResponseCallback for an example.
Otherwise you will have to rethink what a |client| is and when it is provided -
ie - before AllocateAndStart. You don't want to delete the VCC just because you
wanted to get the available formats.

You should also make sure GetDevicesSupportedFormats always return- even if an
error occur or the function is not implemented. It will be very hard to use
unless you know that you always get a result.

Have you thought about how this will be used? 

[mcasas, 2013/10/02 08:13:23]

Done.

 };
 
 // VideoCaptureDevice1 is a bridge to an older API against which