Fix MediaSource code so it can handle HE-AAC content that uses implicit signalling.

media/mp4/aac_unittest.cc

Index: media/mp4/aac_unittest.cc
diff --git a/media/mp4/aac_unittest.cc b/media/mp4/aac_unittest.cc
index 2f61de509b1dd85168eff0a563274612ab778416..f0225675b6d0ccb3cf9fc0f4936f6c8787d86710 100644
--- a/media/mp4/aac_unittest.cc
+++ b/media/mp4/aac_unittest.cc
@@ -18,7 +18,7 @@ TEST(AACTest, BasicProfileTest) {
   data.assign(buffer, buffer + sizeof(buffer));
 
   EXPECT_TRUE(aac.Parse(data));
-  EXPECT_EQ(aac.frequency(), 44100u);
+  EXPECT_EQ(aac.GetOutputSamplesPerSecond(false), 44100);
   EXPECT_EQ(aac.channel_layout(), CHANNEL_LAYOUT_STEREO);
 }
 
@@ -30,7 +30,7 @@ TEST(AACTest, ExtensionTest) {
   data.assign(buffer, buffer + sizeof(buffer));
 
   EXPECT_TRUE(aac.Parse(data));
-  EXPECT_EQ(aac.frequency(), 48000u);
+  EXPECT_EQ(aac.GetOutputSamplesPerSecond(false), 48000);
   EXPECT_EQ(aac.channel_layout(), CHANNEL_LAYOUT_STEREO);
 }
 
@@ -42,7 +42,7 @@ TEST(AACTest, SixChannelTest) {
   data.assign(buffer, buffer + sizeof(buffer));
 
   EXPECT_TRUE(aac.Parse(data));
-  EXPECT_EQ(aac.frequency(), 48000u);
+  EXPECT_EQ(aac.GetOutputSamplesPerSecond(false), 48000);
   EXPECT_EQ(aac.channel_layout(), CHANNEL_LAYOUT_5_1);
 }