We should probably add test expectations to avoid this many warnings:

GMOCK WARNING:
Uninteresting mock function call - taking default action specified at:
../../content/browser/media/session/media_session_impl_browsertest.cc:48:
    Function call: RequestAudioFocus(4-byte object <00-00 00-00>)
          Returns: true
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: MediaSessionStateChanged(true, false)
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: MediaSessionStateChanged(true, true)
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: AbandonAudioFocus()
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: MediaSessionStateChanged(false, true)
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - taking default action specified at:
../../content/browser/media/session/media_session_impl_browsertest.cc:48:
    Function call: RequestAudioFocus(4-byte object <00-00 00-00>)
          Returns: true
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: MediaSessionStateChanged(true, false)
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: MediaSessionStateChanged(true, false)
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: MediaSessionStateChanged(true, true)
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.

GMOCK WARNING:
Uninteresting mock function call - returning directly.
    Function call: AbandonAudioFocus()
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See http://code.google.com/p/googlemock/wiki/CookBook#Knowing_When_to_Expect for details.