Adding NetEq performance test to webrtc_perf_tests

The performance test is based on the neteq4_speed_test application. The
bulk of the test code is extracted into a test class, and included into
the neteq_unittest_tools target. The actual gtest that runs the
performance test is implemented in neteq_performance_unittest.cc, and
built as a part of webrtc_perf_tests.

The old stand-alone test application is now made dependent on the new
test class, to avoid code duplication.

BUG=2397
R=andrew@webrtc.org, kjellander@webrtc.org, turaj@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/6749004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5362 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_coding/neteq/neteq.gypi

@@ -167,6 +167,7 @@
             'PCM16B',
             'neteq_unittest_tools',
             '<(DEPTH)/third_party/gflags/gflags.gyp:gflags',
+            '<(webrtc_root)/test/test.gyp:test_support_main',
           ],
           'sources': [
             'test/neteq_speed_test.cc',