Revert of No longer requiring pixel output for WebRTC tests. (patchset #4...

Revert of No longer requiring pixel output for WebRTC tests. (patchset #4 id:60001 of https://codereview.chromium.org/611953004/)

Reason for revert:
Turns out this change makes video+canvas grabbing produce junk; this is not good since our tests depend on that working. Reverting.

Original issue's description:
> No longer requiring pixel output for WebRTC tests.
>
> We used to require pixel output for our canvas-scraping, but that
> appears to no longer be required. This speeds up the test 3x on my
> win machine, from 30 seconds to about 10.
>
> The content_browsertests on ChromeOS will still enable pixel
> output since it seems the requirements there are different - video
> tags will not work unless that is enabled, it seems. I think
> that's fine since our original problem was with the browser_tests
> anyway, and I think the content_browsertests are probably fast
> enough on ChromeOS anyway (whereas the browser_tests weren't).
>
> BUG=396505
>
> Committed: https://crrev.com/e6a342dcab57c3a2de1fd21301f37fdf3f8ad070
> Cr-Commit-Position: refs/heads/master@{#297654}

TBR=tommi@chromium.org,xians@google.com
NOTREECHECKS=true
NOTRY=true
BUG=396505

Review URL: https://codereview.chromium.org/619003003

Cr-Commit-Position: refs/heads/master@{#297800}

chrome/browser/media/chrome_webrtc_browsertest.cc

@@ -40,7 +40,15 @@ class WebRtcBrowserTest : public WebRtcTestBase {
   }
 };
 
-IN_PROC_BROWSER_TEST_F(WebRtcBrowserTest, RunsAudioVideoWebRTCCallInTwoTabs) {
+#if defined(OS_WIN) || defined(OS_CHROMEOS)
+// http://crbug.com/396505
+#define MAYBE_RunsAudioVideoWebRTCCallInTwoTabs \
+    DISABLED_RunsAudioVideoWebRTCCallInTwoTabs
+#else
+#define MAYBE_RunsAudioVideoWebRTCCallInTwoTabs RunsAudioVideoWebRTCCallInTwoTabs
+#endif
+IN_PROC_BROWSER_TEST_F(WebRtcBrowserTest,
+                       MAYBE_RunsAudioVideoWebRTCCallInTwoTabs) {
   if (OnWinXp()) return;
 
   ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());

chrome/browser/media/webrtc_browsertest_base.cc

@@ -82,6 +82,8 @@ WebRtcTestBase::WebRtcTestBase(): detect_errors_in_javascript_(false) {
   // set operation is idempotent.
   logging::SetLogMessageHandler(&JavascriptErrorDetectingLogHandler);
   hit_javascript_errors_.Get() = false;
+
+  EnablePixelOutput();
 }
 
 WebRtcTestBase::~WebRtcTestBase() {

content/test/webrtc_content_browsertest_base.cc

@@ -34,11 +34,9 @@ void WebRtcContentBrowserTest::SetUpCommandLine(CommandLine* command_line) {
 }
 
 void WebRtcContentBrowserTest::SetUp() {
-  // This is needed lest we break on some virtual machines and weird bot
-  // configs, like ChromeOS and Win x64 swarming.
   EnablePixelOutput();
 #if defined(OS_CHROMEOS)
-  chromeos::CrasAudioHandler::InitializeForTesting();
+    chromeos::CrasAudioHandler::InitializeForTesting();
 #endif
   ContentBrowserTest::SetUp();
 }