Fix and enable ReinitRenderersWhileVideoTrackIsDisabled

Added kNoClockless flag in the test. This is expected to fix the
flake.

Bug: 788387
Change-Id: Ife4a443ef30d4f9b656e52ece3c1025cee5c0a96
Reviewed-on: https://chromium-review.googlesource.com/809507
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521850}

media/test/pipeline_integration_test.cc

@@ -833,10 +833,8 @@ TEST_F(PipelineIntegrationTest, ReinitRenderersWhileAudioTrackIsDisabled) {
   Stop();
 }
 
-// The test is flaky, see https://crbug.com/788387.
-TEST_F(PipelineIntegrationTest,
-       DISABLED_ReinitRenderersWhileVideoTrackIsDisabled) {
-  ASSERT_EQ(PIPELINE_OK, Start("bear-320x240.webm", kHashed));
+TEST_F(PipelineIntegrationTest, ReinitRenderersWhileVideoTrackIsDisabled) {
+  ASSERT_EQ(PIPELINE_OK, Start("bear-320x240.webm", kHashed | kNoClockless));
   Play();
 
   // These get triggered every time playback is resumed.