Add functions to interact with ASan and MSan, and some sample uses

webrtc/modules/audio_coding/neteq/neteq_impl.cc

Index: webrtc/modules/audio_coding/neteq/neteq_impl.cc
diff --git a/webrtc/modules/audio_coding/neteq/neteq_impl.cc b/webrtc/modules/audio_coding/neteq/neteq_impl.cc
index 78e31121848d166826239086835678c051280cd7..5100cd226f0e1bfcd134b56426a1a4ceaf897e10 100644
--- a/webrtc/modules/audio_coding/neteq/neteq_impl.cc
+++ b/webrtc/modules/audio_coding/neteq/neteq_impl.cc
@@ -19,6 +19,7 @@
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/safe_conversions.h"
+#include "webrtc/base/sanitizer.h"
 #include "webrtc/base/trace_event.h"
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 #include "webrtc/modules/audio_coding/codecs/audio_decoder.h"
@@ -134,6 +135,7 @@ NetEqImpl::~NetEqImpl() = default;
 int NetEqImpl::InsertPacket(const WebRtcRTPHeader& rtp_header,
                             rtc::ArrayView<const uint8_t> payload,
                             uint32_t receive_timestamp) {
+  rtc::MsanCheckInitialized(payload);

[kwiberg-webrtc, 2016/08/30 19:55:28]

This is the sort of rtc::MsanCheckInitialized() call one would like to see. It's
very easy to see what it does.

   TRACE_EVENT0("webrtc", "NetEqImpl::InsertPacket");
   rtc::CritScope lock(&crit_sect_);
   int error =