Add live mode detection in WebM MediaSource parser.

media/formats/webm/webm_info_parser.cc

Index: media/formats/webm/webm_info_parser.cc
diff --git a/media/formats/webm/webm_info_parser.cc b/media/formats/webm/webm_info_parser.cc
index ac4f08c40469f14f20136e4f42fe583268d95495..5a2955dbee09a17ca91197ff0d846a714bdda37d 100644
--- a/media/formats/webm/webm_info_parser.cc
+++ b/media/formats/webm/webm_info_parser.cc
@@ -74,6 +74,28 @@ bool WebMInfoParser::OnFloat(int id, double val) {
 }
 
 bool WebMInfoParser::OnBinary(int id, const uint8* data, int size) {
+  if (id == kWebMIdDateUTC) {
+    const int kDateUTCSize = 8;
+    if (size != kDateUTCSize) {
+      DVLOG(1) << "Invalid DateUTC size: " << size;
+      return false;
+    }
+
+    // Parse 64-bit big-endian integer.
+    int64 date_value = 0;
+    for (int i = 0; i < kDateUTCSize; ++i) {
+      date_value = (date_value << 8) | data[i];
+    }
+
+    // DateUTC is specified in nanoseconds from 0:00 on January 1st, 2001.
+    base::Time::Exploded millennium_exploded;
+    memset(&millennium_exploded, 0, sizeof(millennium_exploded));
+    millennium_exploded.year = 2001;
+    millennium_exploded.month = 1;
+    millennium_exploded.day_of_month = 1;
+    date_utc_ = base::Time::FromUTCExploded(millennium_exploded) +
+                base::TimeDelta::FromMicroseconds(date_value / 1000LL);
+  }
   return true;
 }