Only report fraction of lost packets if report_block_stats has been updated.

R=holmer@google.com, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/33939004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@8108 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/video_engine/report_block_stats_unittest.cc b/video_engine/report_block_stats_unittest.cc
index 10c4104..e688d2e 100644
--- a/video_engine/report_block_stats_unittest.cc
+++ b/video_engine/report_block_stats_unittest.cc
@@ -129,11 +129,11 @@
 TEST_F(ReportBlockStatsTest, StoreAndGetFractionLost) {
   const uint32_t kRemoteSsrc = 1;
   ReportBlockStats stats;
-  EXPECT_EQ(0, stats.FractionLostInPercent());
+  EXPECT_EQ(-1, stats.FractionLostInPercent());
 
-  // First block => 0%
+  // First block.
   stats.Store(RtcpReportBlockToRtcpStatistics(block1_1_), kRemoteSsrc, kSsrc1);
-  EXPECT_EQ(0, stats.FractionLostInPercent());
+  EXPECT_EQ(-1, stats.FractionLostInPercent());
   // fl: 100 * (15-10) / (24100-24000) = 5%
   stats.Store(RtcpReportBlockToRtcpStatistics(block1_2_), kRemoteSsrc, kSsrc1);
   EXPECT_EQ(5, stats.FractionLostInPercent());