Implement software fallback for PPB_VideoDecoder.

gpu/gpu_ipc.gypi

Index: gpu/gpu_ipc.gypi
diff --git a/gpu/gpu_ipc.gypi b/gpu/gpu_ipc.gypi
index d1cb292ab2f8376a7d7b0af2be4254edafc03d69..a5538941c328870f071ed1069f1a693dc2910826 100644
--- a/gpu/gpu_ipc.gypi
+++ b/gpu/gpu_ipc.gypi
@@ -18,6 +18,11 @@
     # This section applies to gpu_ipc_win64, used by the NaCl Win64 helper
     # (nacl64.exe).
     ['nacl_win64_target==1', {
+      # needed for messages containing std::vector<gpu::Mailbox>.
+      'sources': [
+        'command_buffer/common/mailbox.cc',
+        'command_buffer/common/mailbox.h',

[dmichael (off chromium), 2014/06/05 23:00:44]

Isn't the IRT also going to need these?

It seems like ideally maybe gpu::Mailbox should also live in gpu/ipc, and go
right under sources with ipc/gpu_command_buffer_traits.*?

[bbudge, 2014/06/06 02:03:46]

It is in the IRT build, pulled in by gpu_nacl.gyp. This is to pull it into the
NaCl helper on Windows. I admit, this seems like a hack to me.

[dmichael (off chromium), 2014/06/06 17:24:00]

Maybe you should make a new appropriate target, like a duplicate of this:
https://code.google.com/p/chromium/codesearch#chromium/src/gpu/gpu.gyp&l=570
I'm a little unsure about the organization of files and targets in gpu, though.

+      ],
       # gpu_ipc_win64 must only link against the 64-bit ipc target.
       'dependencies!': [
         '../ipc/ipc.gyp:ipc',