Add a GUID to base::SharedMemoryHandle.

chrome/gpu/arc_gpu_video_decode_accelerator.cc

Index: chrome/gpu/arc_gpu_video_decode_accelerator.cc
diff --git a/chrome/gpu/arc_gpu_video_decode_accelerator.cc b/chrome/gpu/arc_gpu_video_decode_accelerator.cc
index d0212aef014d6768ec1769fef8950d00650ab180..3ecb5635a4599c9ec570795cd8fb802570a0064c 100644
--- a/chrome/gpu/arc_gpu_video_decode_accelerator.cc
+++ b/chrome/gpu/arc_gpu_video_decode_accelerator.cc
@@ -9,6 +9,7 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/numerics/safe_math.h"
 #include "base/run_loop.h"
+#include "base/unguessable_token.h"
 #include "media/base/video_frame.h"
 #include "media/gpu/gpu_video_decode_accelerator_factory.h"
 
@@ -295,9 +296,11 @@ void ArcGpuVideoDecodeAccelerator::UseBuffer(PortType port,
         return;
       }
       CreateInputRecord(bitstream_buffer_id, index, metadata.timestamp);
+      // TODO(rockot): Pass GUIDs through Mojo. https://crbug.com/713763.

[Ken Rockot(use gerrit already), 2017/05/04 17:54:50]

not sure what Mojo has to do with this bit of code really. Looks like the FD
comes from explicitly duping the FD of another SharedMemoryhandle?

[erikchen, 2017/05/04 19:21:13]

This comes from:
GpuArcVideoService::BindSharedMemory
https://cs.chromium.org/chromium/src/chrome/gpu/gpu_arc_video_service.cc?type...

which gets the FD from a mojo handle: 
"""
base::ScopedFD fd = UnwrapFdFromMojoHandle(std::move(ashmem_handle));
"""

I've added a TODO to myself to pass through the mojo handle, but I've left the
TODO for you as well.

+      base::UnguessableToken guid = base::UnguessableToken::Create();
       vda_->Decode(media::BitstreamBuffer(
           bitstream_buffer_id,
-          base::SharedMemoryHandle(base::FileDescriptor(dup_fd, true)),
+          base::SharedMemoryHandle(base::FileDescriptor(dup_fd, true), guid),
           metadata.bytes_used, input_info->offset));
       break;
     }