[Cronet] Move buffer refptr to closure BidirectionalStream::Read and Write().

This avoids immediate dereferencing when local scoped_refptr() goes out of scope.

Change-Id: Ibf7bc85ca23cd36d8c1e527edb2a70e9d081e8db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1846351
Commit-Queue: Zhongyi Shi <zhongyi@chromium.org>
Auto-Submit: Misha Efimov <mef@chromium.org>
Reviewed-by: Zhongyi Shi <zhongyi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703787}

components/grpc_support/bidirectional_stream.cc

@@ -114,7 +114,7 @@ bool BidirectionalStream::ReadData(char* buffer, int capacity) {
 
   PostToNetworkThread(
       FROM_HERE, base::BindOnce(&BidirectionalStream::ReadDataOnNetworkThread,
-                                weak_this_, read_buffer, capacity));
+                                weak_this_, std::move(read_buffer), capacity));
   return true;
 }
 
@@ -130,7 +130,8 @@ bool BidirectionalStream::WriteData(const char* buffer,
   PostToNetworkThread(
       FROM_HERE,
       base::BindOnce(&BidirectionalStream::WriteDataOnNetworkThread, weak_this_,
-                     write_buffer, count, end_of_stream));
+                     std::move(write_buffer), count, end_of_stream));
+
   return true;
 }