Allow FakeVideoCaptureDeviceFactory to specify number of supported formats per device.

media/capture/video/fake_video_capture_device_unittest.cc

Index: media/capture/video/fake_video_capture_device_unittest.cc
diff --git a/media/capture/video/fake_video_capture_device_unittest.cc b/media/capture/video/fake_video_capture_device_unittest.cc
index c128ad96d49fa74e7ca9cd68df5f9a20a6b8866b..cdf8c07bb51349df165fb9c31b531b7c7ac34ead 100644
--- a/media/capture/video/fake_video_capture_device_unittest.cc
+++ b/media/capture/video/fake_video_capture_device_unittest.cc
@@ -495,6 +495,20 @@ TEST_F(FakeVideoCaptureDeviceTest, TakePhoto) {
   device->StopAndDeAllocate();
 }
 
+TEST_F(FakeVideoCaptureDeviceTest, ZeroFormats) {
+  base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+      switches::kUseFakeDeviceForMediaStream, "device-count=2,format-count=0");
+  std::unique_ptr<VideoCaptureDeviceDescriptors> descriptors(
+      EnumerateDevices());
+  ASSERT_EQ(2u, descriptors->size());
+  for (const auto& descriptor : *descriptors) {
+    VideoCaptureFormats supported_formats;
+    video_capture_device_factory_->GetSupportedFormats(descriptor,
+                                                       &supported_formats);
+    EXPECT_EQ(0u, supported_formats.size());
+  }
+}
+
 TEST_P(FakeVideoCaptureDeviceCommandLineTest, FrameRateAndDeviceCount) {
   base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
       switches::kUseFakeDeviceForMediaStream, GetParam().argument);