Implementing FlushMappedBufferRange in GPU command buffer.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
index 72c8ded6cf62026ef5272cd9f32fecc219275af4..a893788edbe88c5540166cca9bbf6387dd74a9a4 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
@@ -407,6 +407,13 @@ error::Error GLES2DecoderPassthroughImpl::DoFlush() {
   return error::kNoError;
 }
 
+error::Error GLES2DecoderPassthroughImpl::DoFlushMappedBufferRange(
+    GLenum target,
+    GLintptr offset,
+    GLsizeiptr size) {
+  return error::kNoError;
+}
+
 error::Error GLES2DecoderPassthroughImpl::DoFramebufferRenderbuffer(
     GLenum target,
     GLenum attachment,