Allow FakeVideoCaptureDeviceFactory to specify number of supported formats per device.

content/browser/renderer_host/media/media_devices_dispatcher_host_unittest.cc

Index: content/browser/renderer_host/media/media_devices_dispatcher_host_unittest.cc
diff --git a/content/browser/renderer_host/media/media_devices_dispatcher_host_unittest.cc b/content/browser/renderer_host/media/media_devices_dispatcher_host_unittest.cc
index c999cc0f6415d4112bb9b6aee18375e07bfc0bd6..c94f7a3809284d89da7d8ee85ffbcdbcd866cd89 100644
--- a/content/browser/renderer_host/media/media_devices_dispatcher_host_unittest.cc
+++ b/content/browser/renderer_host/media/media_devices_dispatcher_host_unittest.cc
@@ -74,11 +74,14 @@ class MediaDevicesDispatcherHostTest : public testing::Test {
   MediaDevicesDispatcherHostTest()
       : thread_bundle_(content::TestBrowserThreadBundle::IO_MAINLOOP),
         origin_(GURL("https://test.com")) {
-    // Make sure we use fake devices to avoid long delays.
+    // Make sure we use fake devices to avoid long delays. Also, have the fake
+    // devices not report any formats in order to force fallback formats to be
+    // used.
     base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
         switches::kUseFakeDeviceForMediaStream,
-        base::StringPrintf("device-count=%zu, video-input-default-id=%s",
-                           kNumFakeVideoDevices, kDefaultVideoDeviceID));
+        base::StringPrintf(
+            "device-count=%zu, video-input-default-id=%s, format-count=0",
+            kNumFakeVideoDevices, kDefaultVideoDeviceID));
     audio_manager_.reset(
         new media::MockAudioManager(base::ThreadTaskRunnerHandle::Get()));
     media_stream_manager_.reset(new MediaStreamManager(audio_manager_.get()));
@@ -124,6 +127,8 @@ class MediaDevicesDispatcherHostTest : public testing::Test {
     EXPECT_EQ(kNumFakeVideoDevices, capabilities.size());
     EXPECT_EQ(expected_first_device_id, capabilities[0]->device_id);
     for (const auto& capability : capabilities) {
+      // Expect at least one format, even if the device is unable to report its
+      // supported formats.
       EXPECT_GT(capability->formats.size(), 1u);
       EXPECT_GT(capability->formats[0].frame_size.width(), 1);
       EXPECT_GT(capability->formats[0].frame_size.height(), 1);