Fixed running gpu process with kOverrideUseGLWithOSMesaForTests.

content/browser/gpu/gpu_data_manager_impl_private.cc

Index: content/browser/gpu/gpu_data_manager_impl_private.cc
diff --git a/content/browser/gpu/gpu_data_manager_impl_private.cc b/content/browser/gpu/gpu_data_manager_impl_private.cc
index bff0dcbb7945b35f97a0752080a5f8123fa6c447..802aa99c2db87f3db8091a486967edf0b1531458 100644
--- a/content/browser/gpu/gpu_data_manager_impl_private.cc
+++ b/content/browser/gpu/gpu_data_manager_impl_private.cc
@@ -527,8 +527,12 @@ void GpuDataManagerImplPrivate::Initialize() {
   }
 
   gpu::GPUInfo gpu_info;
-  if (command_line->GetSwitchValueASCII(switches::kUseGL) ==
-      gl::kGLImplementationOSMesaName) {
+  const bool force_osmesa =
+      (command_line->GetSwitchValueASCII(switches::kUseGL) ==
+       gl::kGLImplementationOSMesaName) ||
+      (!command_line->HasSwitch(switches::kUseGL) &&

[danakj, 2016/06/23 20:01:13]

Ideally we never have both kUseGL and kOverrideUseGL, perhaps you can DCHECK
that instead? It may be some tests are setting it though since I last looked at
this and did the KOverrideUseGL thing, and we'd need to fix them. I thought I
was DCHECKing that kUseGL wasn't present in BrowserTestBase but I don't see it
right now.

LGTM otherwise.

+       command_line->HasSwitch(switches::kOverrideUseGLWithOSMesaForTests));
+  if (force_osmesa) {
     // If using the OSMesa GL implementation, use fake vendor and device ids to
     // make sure it never gets blacklisted. This is better than simply
     // cancelling GPUInfo gathering as it allows us to proceed with loading the