getUserMedia: handle the device starting status report.

content/renderer/media/video_capture_impl_manager_unittest.cc

Index: content/renderer/media/video_capture_impl_manager_unittest.cc
diff --git a/content/renderer/media/video_capture_impl_manager_unittest.cc b/content/renderer/media/video_capture_impl_manager_unittest.cc
index a68a26b063433642d243c921673969c4c2c05d8c..ea3478f5214c942747c0773b3fd6f2c1751943aa 100644
--- a/content/renderer/media/video_capture_impl_manager_unittest.cc
+++ b/content/renderer/media/video_capture_impl_manager_unittest.cc
@@ -63,6 +63,8 @@ class MockVideoCaptureImpl : public VideoCaptureImpl,
              mojom::VideoCaptureObserverPtr observer) override {
     // For every Start(), expect a corresponding Stop() call.
     EXPECT_CALL(*this, Stop(_));
+    // Simulate device started.
+    OnStateChanged(mojom::VideoCaptureState::STARTED);
   }
 
   MOCK_METHOD1(Stop, void(int32_t));
@@ -131,8 +133,13 @@ class VideoCaptureImplManagerTest : public ::testing::Test,
       bool same_session_id) {
     base::RunLoop run_loop;
     base::Closure quit_closure = BindToCurrentLoop(run_loop.QuitClosure());
-    EXPECT_CALL(*this, OnStarted(_)).Times(kNumClients - 1)
-        .RetiresOnSaturation();
+    if (!same_session_id) {
+      // |OnStarted| will only be received once from each device if there are
+      // multiple request to the same device.
+      EXPECT_CALL(*this, OnStarted(_))
+          .Times(kNumClients - 1)
+          .RetiresOnSaturation();
+    }
     EXPECT_CALL(*this, OnStarted(_)).WillOnce(RunClosure(quit_closure))
         .RetiresOnSaturation();

[chfremer, 2017/03/02 17:56:10]

If this worked before, it will probably still work after the change.

While reading, I stumbled over the two EXPECT_CALL statements for OnStarted(). I
understand that the second EXPECT_CALL is separate from the first, because it is
supposed to call |quit_closure|. However, it is not clear to me whether or not
gmock guarantees that it will match the first |kNumClient - 1| invocations to
the first (and not the second) EXPECT_CALL unless we use InSequence, see the
section on RetiresOnSaturation in [1].

[1]
https://github.com/google/googletest/blob/master/googlemock/docs/ForDummies.md

[braveyao, 2017/03/03 17:53:12]

Done.

     std::array<base::Closure, kNumClients> stop_callbacks;