Tag some of Mojo heap allocations for the heap profiler.

media/mojo/common/mojo_decoder_buffer_converter.cc

Index: media/mojo/common/mojo_decoder_buffer_converter.cc
diff --git a/media/mojo/common/mojo_decoder_buffer_converter.cc b/media/mojo/common/mojo_decoder_buffer_converter.cc
index 0a12aa6067ec6521bb1b98144b7900f4c75b0bb0..32080d3af4458ff28707a811c51bec9e38035b8f 100644
--- a/media/mojo/common/mojo_decoder_buffer_converter.cc
+++ b/media/mojo/common/mojo_decoder_buffer_converter.cc
@@ -63,7 +63,9 @@ std::unique_ptr<MojoDecoderBufferReader> MojoDecoderBufferReader::Create(
 
 MojoDecoderBufferReader::MojoDecoderBufferReader(
     mojo::ScopedDataPipeConsumerHandle consumer_handle)
-    : consumer_handle_(std::move(consumer_handle)), bytes_read_(0) {
+    : consumer_handle_(std::move(consumer_handle)),
+      pipe_watcher_(FROM_HERE),
+      bytes_read_(0) {
   DVLOG(1) << __func__;
 
   MojoResult result =
@@ -183,7 +185,9 @@ std::unique_ptr<MojoDecoderBufferWriter> MojoDecoderBufferWriter::Create(
 
 MojoDecoderBufferWriter::MojoDecoderBufferWriter(
     mojo::ScopedDataPipeProducerHandle producer_handle)
-    : producer_handle_(std::move(producer_handle)), bytes_written_(0) {
+    : producer_handle_(std::move(producer_handle)),
+      pipe_watcher_(FROM_HERE),
+      bytes_written_(0) {
   DVLOG(1) << __func__;
 
   MojoResult result =