Make FakeVideoCaptureDeviceFactory configurable to arbitrary fake device configurations

media/capture/video/fake_video_capture_device_factory.h

Index: media/capture/video/fake_video_capture_device_factory.h
diff --git a/media/capture/video/fake_video_capture_device_factory.h b/media/capture/video/fake_video_capture_device_factory.h
index 7fb0597fe7e99f61ae5def6f4ce500a1b4b738a3..06ed42ed1ee1c2a05f787df27b8c1ae4a6688c0f 100644
--- a/media/capture/video/fake_video_capture_device_factory.h
+++ b/media/capture/video/fake_video_capture_device_factory.h
@@ -10,20 +10,56 @@
 
 namespace media {
 
+struct CAPTURE_EXPORT FakeVideoCaptureDeviceSettings {
+  FakeVideoCaptureDeviceSettings();
+  ~FakeVideoCaptureDeviceSettings();
+  FakeVideoCaptureDeviceSettings(const FakeVideoCaptureDeviceSettings& other);
+
+  std::string device_id;
+  FakeVideoCaptureDevice::DeliveryMode delivery_mode;
+  VideoCaptureFormats supported_formats;
+};
+
 // Implementation of VideoCaptureDeviceFactory that creates fake devices
 // that generate test output frames.
-// By default, the factory has one device outputting I420.
-// When increasing the number of devices using set_number_of_devices(), the
-// second device will use Y16, and any devices beyond that will use I420.
-// By default, the delivery mode of all devices is USE_OWN_BUFFERS.
-// This, as well as other parameters, can be changed using command-line flags.
-// See implementation of method ParseCommandLine() for details.
+// By default, the factory has one device outputting I420 with
+// USE_DEVICE_INTERNAL_BUFFERS. It supports a default set of resolutions.
+// When a resolution is requested that is not part of the default set, it snaps
+// to the resolution with the next larger width. It supports all frame rates
+// within a default allowed range.
 class CAPTURE_EXPORT FakeVideoCaptureDeviceFactory
     : public VideoCaptureDeviceFactory {
  public:
   FakeVideoCaptureDeviceFactory();
-  ~FakeVideoCaptureDeviceFactory() override {}
+  ~FakeVideoCaptureDeviceFactory() override;
+
+  static std::unique_ptr<VideoCaptureDevice> CreateDeviceWithSupportedFormats(
+      FakeVideoCaptureDevice::DeliveryMode delivery_mode,
+      const VideoCaptureFormats& formats);
+
+  static std::unique_ptr<VideoCaptureDevice> CreateDeviceWithDefaultResolutions(
+      VideoPixelFormat pixel_format,
+      FakeVideoCaptureDevice::DeliveryMode delivery_mode,
+      float frame_rate);
+
+  // Creates a device that reports OnError() when AllocateAndStart() is called.
+  static std::unique_ptr<VideoCaptureDevice> CreateErrorDevice();
 
+  static void ParseFakeDevicesConfigFromOptionsString(
+      const std::string options_string,
+      std::vector<FakeVideoCaptureDeviceSettings>* config);
+
+  // All devices use the default set of resolution, the default range for
+  // allowed frame rates, as well as USE_DEVICE_INTERNAL_BUFFERS.
+  // Device 0 outputs I420.
+  // Device 1 outputs Y16.
+  // Device 2 outputs MJPEG.
+  // All additional devices output I420.
+  void SetToDefaultDevicesConfig(int device_count);
+  void SetToCustomDevicesConfig(
+      const std::vector<FakeVideoCaptureDeviceSettings>& config);
+
+  // VideoCaptureDeviceFactory implementation:
   std::unique_ptr<VideoCaptureDevice> CreateDevice(
       const VideoCaptureDeviceDescriptor& device_descriptor) override;
   void GetDeviceDescriptors(
@@ -32,22 +68,13 @@ class CAPTURE_EXPORT FakeVideoCaptureDeviceFactory
       const VideoCaptureDeviceDescriptor& device_descriptor,
       VideoCaptureFormats* supported_formats) override;
 
-  void set_number_of_devices(int number_of_devices) {
-    DCHECK(thread_checker_.CalledOnValidThread());
-    number_of_devices_ = number_of_devices;
-  }
   int number_of_devices() {
     DCHECK(thread_checker_.CalledOnValidThread());
-    return number_of_devices_;
+    return static_cast<int>(devices_config_.size());
   }
 
  private:
-  void ParseCommandLine();
-
-  int number_of_devices_;
-  FakeVideoCaptureDeviceMaker::DeliveryMode delivery_mode_;
-  float frame_rate_;
-  bool command_line_parsed_ = false;
+  std::vector<FakeVideoCaptureDeviceSettings> devices_config_;
 };
 
 }  // namespace media