Sample build: https://uberchromegw.corp.google.com/i/chromium.android/builders/Marshmallow%20Tablet%20Tester/builds/4476

Failed 3 times in the last 3 builds, and has been flaky for as far as I can go in the bot's history.

Error in testGrantAccess:
java.util.concurrent.TimeoutException: waitForCallback timed out!
	at org.chromium.content.browser.test.util.CallbackHelper.waitForCallback(CallbackHelper.java:184)
	at org.chromium.content.browser.test.util.CallbackHelper.waitForCallback(CallbackHelper.java:192)
	at org.chromium.content.browser.test.util.CallbackHelper.waitForCallback(CallbackHelper.java:198)
	at org.chromium.android_webview.test.MediaAccessPermissionRequestTest.testGrantAccess(MediaAccessPermissionRequestTest.java:93)
	at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
	at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
	at android.test.ActivityInstrumentationTestCase2.runTest(ActivityInstrumentationTestCase2.java:192)
	at org.chromium.base.test.BaseTestResult.runParameterized(BaseTestResult.java:161)
	at org.chromium.base.test.BaseTestResult.run(BaseTestResult.java:124)
	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
	at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
	at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:555)
	at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1879)

I'm going to disable it, as it seems like a similar cause to issue 620890