Added IsInBeam to mock_nonlinear_beamformer.h

Review URL: https://codereview.webrtc.org/1262853003

Cr-Commit-Position: refs/heads/master@{#9655}

webrtc/modules/audio_processing/beamformer/mock_nonlinear_beamformer.h

@@ -25,6 +25,7 @@ class MockNonlinearBeamformer : public NonlinearBeamformer {
   MOCK_METHOD2(Initialize, void(int chunk_size_ms, int sample_rate_hz));
   MOCK_METHOD2(ProcessChunk, void(const ChannelBuffer<float>& input,
                                   ChannelBuffer<float>* output));
+  MOCK_METHOD1(IsInBeam, bool(const SphericalPointf& spherical_point));
   MOCK_METHOD0(is_target_present, bool());
 };