Relanding WebRTC real webcam browsertest for Android.

content/test/webrtc_content_browsertest_base.cc

Index: content/test/webrtc_content_browsertest_base.cc
diff --git a/content/test/webrtc_content_browsertest_base.cc b/content/test/webrtc_content_browsertest_base.cc
index e6c3b4600815849a6eb3ca9e5635179dc845fe63..f37eb900894c7efe51b49fb96e4ec33b1e9d207d 100644
--- a/content/test/webrtc_content_browsertest_base.cc
+++ b/content/test/webrtc_content_browsertest_base.cc
@@ -24,12 +24,11 @@
 namespace content {
 
 void WebRtcContentBrowserTest::SetUpCommandLine(CommandLine* command_line) {
-  // We need fake devices in this test since we want to run on naked VMs. We
-  // assume these switches are set by default in content_browsertests.
-  ASSERT_TRUE(CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kUseFakeDeviceForMediaStream));
+  // Assume this is set by the content test launcher.
   ASSERT_TRUE(CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kUseFakeUIForMediaStream));
+  ASSERT_TRUE(CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kUseFakeDeviceForMediaStream));
 
   // Always include loopback interface in network list, in case the test device
   // doesn't have other interfaces available.
@@ -38,6 +37,7 @@ void WebRtcContentBrowserTest::SetUpCommandLine(CommandLine* command_line) {
 }
 
 void WebRtcContentBrowserTest::SetUp() {
+  // We need pixel output when we dig pixels out of video tags for verification.
   EnablePixelOutput();
 #if defined(OS_CHROMEOS)
     chromeos::CrasAudioHandler::InitializeForTesting();