Change ChunkDemuxerStream/SourceBufferStream memory limit to size_t type

media/filters/source_buffer_platform_lowmem.cc

Index: media/filters/source_buffer_platform_lowmem.cc
diff --git a/media/filters/source_buffer_platform_lowmem.cc b/media/filters/source_buffer_platform_lowmem.cc
index 79757cd81c194590ef6ea4284764ffdb0d51f419..90ed051b6cfef1a7406a5ed510d449a4064154f0 100644
--- a/media/filters/source_buffer_platform_lowmem.cc
+++ b/media/filters/source_buffer_platform_lowmem.cc
@@ -8,7 +8,7 @@ namespace media {
 
 // 2MB: approximately 1 minute of 256Kbps content.
 // 30MB: approximately 1 minute of 4Mbps content.
-const int kSourceBufferAudioMemoryLimit = 2 * 1024 * 1024;
-const int kSourceBufferVideoMemoryLimit = 30 * 1024 * 1024;
+const size_t kSourceBufferAudioMemoryLimit = 2 * 1024 * 1024;
+const size_t kSourceBufferVideoMemoryLimit = 30 * 1024 * 1024;
 
 }  // namespace media