Do not lose secondary gpus and make sure to have an active gpu on multiple gpu configurations

content/gpu/gpu_main.cc

Index: content/gpu/gpu_main.cc
diff --git a/content/gpu/gpu_main.cc b/content/gpu/gpu_main.cc
index 7ffa59e4468e611e614de4026b9e6a2f5f476ae0..9805e9b75fe990c51c3965bdf22c113b1e4ba25c 100644
--- a/content/gpu/gpu_main.cc
+++ b/content/gpu/gpu_main.cc
@@ -442,6 +442,10 @@ void GetGpuInfoFromCommandLine(gpu::GPUInfo& gpu_info,
       command_line.GetSwitchValueASCII(switches::kGpuDriverVendor);
   gpu_info.driver_version =
       command_line.GetSwitchValueASCII(switches::kGpuDriverVersion);
+  gpu::ParseSecondaryGpuDevicesFromCommandLine(command_line, false, &gpu_info);
+  if (gpu_info.secondary_gpus.size() == 0)
+    gpu_info.gpu.active = true;

[Zhenyao Mo, 2016/04/21 17:03:37]

This is better, but still doesn't address the problem when multiple GPUs are
passed from browser process to GPU process, which one is active.  I suggest in
multiple GPU situation, you pass another switch to identify which GPU is active.
If you decide to pass all the information including secondary GPUs, it doesn't
make sense you leave out the "active" bit.

[Julien Isorce Samsung, 2016/04/21 23:27:08]

Done, I added kGpuActiveDeviceID.

+
   GetContentClient()->SetGpuInfo(gpu_info);
 }