Don't crash when splices are in the past due to bad media.

media/base/audio_splicer_unittest.cc

Index: media/base/audio_splicer_unittest.cc
diff --git a/media/base/audio_splicer_unittest.cc b/media/base/audio_splicer_unittest.cc
index e6de2c62ed330ad9433993bd62b5dfbd0ce80ac5..86131bf48747448a2a806eecdb15e1d70808e774 100644
--- a/media/base/audio_splicer_unittest.cc
+++ b/media/base/audio_splicer_unittest.cc
@@ -720,4 +720,48 @@ TEST_F(AudioSplicerTest, IncorrectlyMarkedSpliceWithBadGap) {
   EXPECT_FALSE(AddInput(second_buffer));
 }
 
+// Ensure we don't crash when a splice frame is incorrectly marked such that the
+// splice timestamp has already passed when SetSpliceTimestamp() is called.
+// This can happen if the encoded timestamps are too far behind the decoded
+// timestamps.
+TEST_F(AudioSplicerTest, IncorrectlyMarkedPastSplice) {
+  const int kBufferSize = 200;
+
+  scoped_refptr<AudioBuffer> first_buffer =
+      GetNextInputBuffer(1.0f, kBufferSize);
+  EXPECT_TRUE(AddInput(first_buffer));
+  VerifyNextBuffer(first_buffer);
+
+  // Start the splice at a timestamp which has already occurred.
+  splicer_.SetSpliceTimestamp(base::TimeDelta());
+
+  scoped_refptr<AudioBuffer> second_buffer =
+      GetNextInputBuffer(0.5f, kBufferSize);
+  EXPECT_TRUE(AddInput(second_buffer));
+  EXPECT_FALSE(splicer_.HasNextBuffer());
+
+  // |third_buffer| will complete the supposed splice.  The buffer size is set
+  // such that unchecked the splicer would try to trim off a negative number of
+  // frames.
+  splicer_.SetSpliceTimestamp(kNoTimestamp());
+  scoped_refptr<AudioBuffer> third_buffer =
+      GetNextInputBuffer(0.0f, kBufferSize * 10);
+  third_buffer->set_timestamp(base::TimeDelta());
+  EXPECT_TRUE(AddInput(third_buffer));
+
+  // The second buffer should come through unmodified.
+  VerifyNextBuffer(second_buffer);
+
+  // The third buffer should be partially dropped since it overlaps the second.
+  ASSERT_TRUE(splicer_.HasNextBuffer());
+  const base::TimeDelta second_buffer_end_ts =
+      second_buffer->timestamp() + second_buffer->duration();
+  scoped_refptr<AudioBuffer> output = splicer_.GetNextBuffer();
+  EXPECT_EQ(second_buffer_end_ts, output->timestamp());
+  EXPECT_EQ(third_buffer->duration() -
+                (second_buffer_end_ts - third_buffer->timestamp()),
+            output->duration());
+  EXPECT_TRUE(VerifyData(output, GetValue(third_buffer)));
+}
+
 }  // namespace media