Refactor webrtc_perf_tests into several source_sets.

webrtc/modules/audio_processing/BUILD.gn

Index: webrtc/modules/audio_processing/BUILD.gn
diff --git a/webrtc/modules/audio_processing/BUILD.gn b/webrtc/modules/audio_processing/BUILD.gn
index 049a4e1d048ddc966c304915da60a1dc9d0150a6..5cbd97d90a50d2590640965a9fbc0203694e3827 100644
--- a/webrtc/modules/audio_processing/BUILD.gn
+++ b/webrtc/modules/audio_processing/BUILD.gn
@@ -411,6 +411,35 @@ if (rtc_include_tests) {
     }
   }
 
+  rtc_source_set("audio_processing_perf_tests") {
+    # Has problems with autogenerated targets on Android and iOS
+    # Dependency chain (there may also be others):
+    #  //webrtc/modules/audio_processing:audio_processing_perf_tests -->
+    #  //webrtc/modules:modules_unittests --[private]-->
+    #  //webrtc/modules:modules_unittests_apk -->
+    #  //webrtc/modules:modules_unittests_apk__create -->
+    #  //webrtc/modules:modules_unittests_apk__create__finalize -->
+    #  //webrtc/modules:modules_unittests_apk__create__package --[private]-->
+    #  //webrtc/modules:_modules_unittests__library
+    check_includes = false
+    testonly = true
+    sources = [
+      "audio_processing_performance_unittest.cc",
+      "level_controller/level_controller_complexity_unittest.cc",
+      "residual_echo_detector_complexity_unittest.cc",
+    ]
+    deps = [
+      ":audio_processing",
+      ":audioproc_test_utils",
+      "//testing/gtest",
+    ]
+    if (rtc_enable_intelligibility_enhancer) {
+      defines = [ "WEBRTC_INTELLIGIBILITY_ENHANCER=1" ]
+    } else {
+      defines = [ "WEBRTC_INTELLIGIBILITY_ENHANCER=0" ]
+    }
+  }
+
   rtc_executable("unpack_aecdump") {
     testonly = true
     sources = [