Fix mpeg-1 layer2 parsing typo.

media/formats/mpeg/mpeg1_audio_stream_parser_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/formats/mpeg/mpeg1_audio_stream_parser.h"
 
 #include <stdint.h>
 
 #include <memory>
 
@@ skipping 30 matching lines @@
       "{ 0K }"
       "EndOfSegment"
       "NewSegment"
       "{ 0K }"
       "{ 0K }"
       "EndOfSegment";
   EXPECT_EQ(expected, ParseFile("sfx.mp3", 17));
   EXPECT_GT(last_audio_config().codec_delay(), 0);
 }
 
+// Test parsing with small prime sized chunks to smoke out "power of
+// 2" field size assumptions.

[chcunningham, 2017/02/22 00:49:04]

Is this just theoretical? I'm not aware of any powers of two assumptions in
media segment length. The API is pretty high level. 

[DaleCurtis, 2017/02/22 00:53:11]

Yes I think it's just theoretical, but that's how all of these parser tests are
written so I just kept the style.

[chcunningham, 2017/02/22 01:13:48]

Sorry, missed that. Your first segment isn't prime (4), so I'd just kill that
comment. 

[DaleCurtis, 2017/02/22 01:20:14]

Done.

+TEST_F(MPEG1AudioStreamParserTest, UnalignedAppendMP2) {
+  const std::string expected =
+      "NewSegment"
+      "{ 0K }"
+      "{ 0K }"

[chcunningham, 2017/02/22 00:49:03]

Why are the timestamps not increasing?

[DaleCurtis, 2017/02/22 00:53:11]

Timestamps restart per append; so the small append size results in a restart of
timestamping everytime. I forget how MSE cleans this up internally; but note
this is the same as the test above.

[chcunningham, 2017/02/22 01:13:48]

Ah, yeah. timestampOffset gets updated at the boundary of the append. 

+      "{ 0K }"
+      "{ 0K }"
+      "EndOfSegment"
+      "NewSegment"
+      "{ 0K }"
+      "{ 0K }"
+      "{ 0K }"
+      "{ 0K }"
+      "{ 0K }"
+      "{ 0K }"
+      "EndOfSegment";
+  EXPECT_EQ(expected, ParseFile("sfx.mp2", 17));
+  EXPECT_GT(last_audio_config().codec_delay(), 0);
+}
+
 // Test parsing with a larger piece size to verify that multiple buffers
 // are passed to |new_buffer_cb_|.
 TEST_F(MPEG1AudioStreamParserTest, UnalignedAppend512) {
   const std::string expected =
       "NewSegment"
       "{ 0K 26K 52K 78K }"
       "EndOfSegment"
       "NewSegment"
       "{ 0K 26K 52K }"
       "{ 0K 26K 52K 78K }"
@@ skipping 30 matching lines @@
   buffer_ptr += kXingRemainingSize;
 
   // Append the first real frame and ensure we get a segment.
   const int kFirstRealFrameSize = 182;
   EXPECT_EQ("NewSegment{ 0K }EndOfSegment",
             ParseData(buffer_ptr, kFirstRealFrameSize));
   EXPECT_TRUE(last_audio_config().IsValidConfig());
 }
 
 }  // namespace media