Cap the memory usage in FFMpegDemuxer.

media/base/decoder_buffer_queue_unittest.cc

Index: media/base/decoder_buffer_queue_unittest.cc
diff --git a/media/base/decoder_buffer_queue_unittest.cc b/media/base/decoder_buffer_queue_unittest.cc
index 32e62db06b1dc79a0efbf9e69f337a88b435c643..1bbb8762f956d71a2f2bbe664db17589e32ed0d5 100644
--- a/media/base/decoder_buffer_queue_unittest.cc
+++ b/media/base/decoder_buffer_queue_unittest.cc
@@ -18,8 +18,8 @@ static base::TimeDelta ToTimeDelta(int seconds) {
 // Helper to create buffers with specified timestamp in seconds.
 //
 // Negative numbers will be converted to kNoTimestamp();
-static scoped_refptr<DecoderBuffer> CreateBuffer(int timestamp) {
-  scoped_refptr<DecoderBuffer> buffer = new DecoderBuffer(0);
+static scoped_refptr<DecoderBuffer> CreateBuffer(int timestamp, int size = 0) {
+  scoped_refptr<DecoderBuffer> buffer = new DecoderBuffer(size);
   buffer->set_timestamp(ToTimeDelta(timestamp));
   buffer->set_duration(ToTimeDelta(0));
   return buffer;
@@ -135,4 +135,28 @@ TEST(DecoderBufferQueueTest, Duration_NoTimestamp) {
   EXPECT_EQ(0, queue.Duration().InSeconds());
 }
 
+TEST(DecoderBufferQueueTest, Size) {
+  DecoderBufferQueue queue;
+  EXPECT_EQ(queue.data_size(), 0);
+
+  queue.Push(CreateBuffer(0, 1200));
+  EXPECT_EQ(queue.data_size(), 1200);
+
+  queue.Push(CreateBuffer(1, 1000));
+  EXPECT_EQ(queue.data_size(), 2200);
+
+  queue.Pop();
+  EXPECT_EQ(queue.data_size(), 1000);
+
+  queue.Push(CreateBuffer(2, 999));
+  queue.Push(CreateBuffer(3, 999));
+  EXPECT_EQ(queue.data_size(), 2998);
+
+  queue.Clear();
+  EXPECT_EQ(queue.data_size(), 0);
+
+  queue.Push(CreateBuffer(4, 1400));
+  EXPECT_EQ(queue.data_size(), 1400);
+}
+
 }  // namespace media