Fix Visual Studio 2015 WebRtc x86 build.

webrtc/modules/audio_processing/audio_processing_impl_locking_unittest.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 180 matching lines @@
     };
 
     auto add_aec_settings = [](const std::vector<TestConfig>& in) {
       std::vector<TestConfig> out;
       AecType aec_types[] = {
           AecType::BasicWebRtcAecSettings, AecType::AecTurnedOff,
           AecType::BasicWebRtcAecSettingsWithExtentedFilter,
           AecType::BasicWebRtcAecSettingsWithDelayAgnosticAec,
           AecType::BasicWebRtcAecSettingsWithAecMobile};
       for (auto test_config : in) {
-        for (auto aec_type : aec_types) {
-          test_config.aec_type = aec_type;
+        // Due to a VisualStudio 2015 compiler issue, the internal loop
+        // variable here cannot override a previously defined name.
+        // In other words "type" cannot be named "aec_type" here.
+        // https://connect.microsoft.com/VisualStudio/feedback/details/2291755
+        for (auto type : aec_types) {
+          test_config.aec_type = type;
           out.push_back(test_config);
         }
       }
       return out;
     };
 
     auto add_settings_scheme = [](const std::vector<TestConfig>& in) {
       std::vector<TestConfig> out;
       RuntimeParameterSettingScheme schemes[] = {
           RuntimeParameterSettingScheme::SparseStreamMetadataChangeScheme,
@@ skipping 911 matching lines @@
     DISABLED_AudioProcessingImplLockExtensive,
     AudioProcessingImplLockTest,
     ::testing::ValuesIn(TestConfig::GenerateExtensiveTestConfigs()));
 
 INSTANTIATE_TEST_CASE_P(
     AudioProcessingImplLockBrief,
     AudioProcessingImplLockTest,
     ::testing::ValuesIn(TestConfig::GenerateBriefTestConfigs()));
 
 }  // namespace webrtc