Use clock_gettime instead of base::TimeTicks::Now() in QUIC

net/quic/platform/impl/quic_chromium_clock.cc

Index: net/quic/platform/impl/quic_chromium_clock.cc
diff --git a/net/quic/platform/impl/quic_chromium_clock.cc b/net/quic/platform/impl/quic_chromium_clock.cc
index cbf1ed1b14e2c94199da029c3ec1a69e13a7a96a..e677bd882c62bed1046426a4fe164167ee990879 100644
--- a/net/quic/platform/impl/quic_chromium_clock.cc
+++ b/net/quic/platform/impl/quic_chromium_clock.cc
@@ -4,6 +4,12 @@
 
 #include "net/quic/platform/impl/quic_chromium_clock.h"
 
+#if defined(OS_IOS)
+#include <time.h>
+
+#include "base/ios/ios_util.h"
+#endif
+
 #include "base/memory/singleton.h"
 #include "base/time/time.h"
 
@@ -23,7 +29,14 @@ QuicTime QuicChromiumClock::ApproximateNow() const {
 }
 
 QuicTime QuicChromiumClock::Now() const {
-  return QuicTime(base::TimeTicks::Now());
+#if defined(OS_IOS)
+  if (base::ios::IsRunningOnIOS10OrLater()) {
+    struct timespec tp;
+    clock_gettime(CLOCK_MONOTONIC, &tp);

[kapishnikov, 2017/05/10 18:10:11]

One extra comment. Maybe we should check the result of clock_gettime() function
and fall back to base::TimeTicks if the result is not '0'. I imagine it should
never happen but who knows.

[Ryan Hamilton, 2017/05/10 19:07:47]

Done. If this sloshes back and forth, that would be terrible but the man page
suggests that if it fails, it'll fail consistently.

+    return CreateTimeFromMicroseconds(tp.tv_sec * 1000000 + tp.tv_nsec / 1000);
+  }
+#endif
+  return CreateTimeFromMicroseconds(base::TimeTicks::Now().ToInternalValue());
 }
 
 QuicWallTime QuicChromiumClock::WallNow() const {