Rename MediaSourceState -> SourceBufferState

media/BUILD.gn

Index: media/BUILD.gn
diff --git a/media/BUILD.gn b/media/BUILD.gn
index 0fd75e26f4dc4d87a8b3fbaccb2cfd603a05f6ce..2cc686abb417945a7d9067fbd91fbe8e2d5d90a1 100644
--- a/media/BUILD.gn
+++ b/media/BUILD.gn
@@ -158,8 +158,6 @@ component("media") {
     "filters/ivf_parser.h",
     "filters/jpeg_parser.cc",
     "filters/jpeg_parser.h",
-    "filters/media_source_state.cc",
-    "filters/media_source_state.h",
     "filters/memory_data_source.cc",
     "filters/memory_data_source.h",
     "filters/opus_audio_decoder.cc",
@@ -170,6 +168,8 @@ component("media") {
     "filters/pipeline_controller.h",
     "filters/source_buffer_range.cc",
     "filters/source_buffer_range.h",
+    "filters/source_buffer_state.cc",
+    "filters/source_buffer_state.h",
     "filters/source_buffer_stream.cc",
     "filters/source_buffer_stream.h",
     "filters/stream_parser_factory.cc",
@@ -547,9 +547,9 @@ test("media_unittests") {
     "filters/h264_parser_unittest.cc",
     "filters/ivf_parser_unittest.cc",
     "filters/jpeg_parser_unittest.cc",
-    "filters/media_source_state_unittest.cc",
     "filters/memory_data_source_unittest.cc",
     "filters/pipeline_controller_unittest.cc",
+    "filters/source_buffer_state_unittest.cc",
     "filters/source_buffer_stream_unittest.cc",
     "filters/video_cadence_estimator_unittest.cc",
     "filters/video_decoder_selector_unittest.cc",