Replace size_t with int in a few media classes.

media/base/data_buffer_unittest.cc

Index: media/base/data_buffer_unittest.cc
diff --git a/media/base/data_buffer_unittest.cc b/media/base/data_buffer_unittest.cc
index 38b73d9c0c7f8f984e6716f2de8df4c60c7d2d55..d685a87a05aeef2056834a525e5c9e83d19984d2 100644
--- a/media/base/data_buffer_unittest.cc
+++ b/media/base/data_buffer_unittest.cc
@@ -9,21 +9,21 @@
 namespace media {
 
 TEST(DataBufferTest, Constructors) {
-  const size_t kTestSize = 10;
+  const int kTestSize = 10;
 
   scoped_refptr<DataBuffer> buffer(new DataBuffer(0));
   EXPECT_FALSE(buffer->GetData());
 
   scoped_refptr<DataBuffer> buffer2(new DataBuffer(kTestSize));
-  EXPECT_EQ(0u, buffer2->GetDataSize());
+  EXPECT_EQ(0, buffer2->GetDataSize());
   EXPECT_EQ(kTestSize, buffer2->GetBufferSize());
 }
 
 TEST(DataBufferTest, ReadingWriting) {
   const char kData[] = "hello";
-  const size_t kDataSize = arraysize(kData);
+  const int kDataSize = arraysize(kData);
   const char kNewData[] = "chromium";
-  const size_t kNewDataSize = arraysize(kNewData);
+  const int kNewDataSize = arraysize(kNewData);
 
   // Create a DataBuffer.
   scoped_refptr<DataBuffer> buffer(new DataBuffer(kDataSize));