Fix WebRtc ninja x86 build using Visual Studio 2015 (set GYP_MSVS_VERSION=2015).

Visual Studio 2015 balks at the implicit truncation of values. Easily fixed with an explicit cast.

Fixed redefinition of CLOCKS_PER_SEC when using Visual Studio 2015 and the Windows 10 SDK. CLOCKS_PER_SEC is also defined in "<WIN10 SDK DIR>\include\10.0.10240.0\ucrt\time.h" and also has the value of 1000

Hiding snprintf definition if building with Visual Studio 2015

Fixed C4573 compiler complaint in audio_processing_impl_locking_unittest.cc.

BUG=webrtc:5183

Review URL: https://codereview.webrtc.org/1412653006

Cr-Commit-Position: refs/heads/master@{#11434}
diff --git a/webrtc/modules/audio_processing/audio_processing_impl_locking_unittest.cc b/webrtc/modules/audio_processing/audio_processing_impl_locking_unittest.cc
index 3d2c71f..2e22b2c 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl_locking_unittest.cc
+++ b/webrtc/modules/audio_processing/audio_processing_impl_locking_unittest.cc
@@ -198,8 +198,12 @@
           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);
         }
       }