X11: Use better visuals for OpenGL

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 96beb775df9b3160d7e407bce87e51bc90d2cc36..1c406ee5e1159ae4d9a0d12fb0a897a15e360a7b 100644
--- a/content/browser/gpu/gpu_data_manager_impl_private.cc
+++ b/content/browser/gpu/gpu_data_manager_impl_private.cc
@@ -50,6 +50,10 @@
 #include "base/win/windows_version.h"
 #endif  // OS_WIN
 
+#if defined(USE_X11) && !defined(OS_CHROMEOS)
+#include "ui/base/x/x11_util_internal.h"  // nogncheck
+#endif
+
 namespace content {
 
 namespace {
@@ -1171,6 +1175,12 @@ void GpuDataManagerImplPrivate::UpdateGpuSwitchingManager(
 }
 
 void GpuDataManagerImplPrivate::NotifyGpuInfoUpdate() {
+#if defined(USE_X11) && !defined(OS_CHROMEOS)
+  // TODO(thomasanderson): figure out what to do with this

[Tom (Use chromium acct), 2016/09/22 19:53:29]

I left this here as a placeholder but I'm not quite sure where to actually put
it.  Maybe just make a GpuInfoObserver and stick it in browser_main_loop.cc
where the disable_transparent_visual stuff got removed?

Also, I don't know how to reliably figure out whether we're using software
compositing.  The "gpu_info_.software_rendering || card_blacklisted_" doesn't
work with --single-process.  And GpuAccessAllowed() returns false without
--disable-gpu before we have the GPUInfo.

+  ui::XVisualManager::GetInstance()->OnGPUInfoChanged(

[piman, 2016/09/22 21:24:54]

This function is called on the IO thread (and sometimes on the UI thread). IIUC,
XVisualManager is intended to be called from the UI thread, so I think this
would cause some races. Maybe it would be better to add a GpuDataManagerObserver
to forward that info? observer_list_ is thread-safe, so the observer would be
called on the same thread it's registered from (the UI thread if added from
BrowserMainLoop).

[Tom (Use chromium acct), 2016/09/23 20:00:37]

Done.  Added GpuDataManagerVisualProxy in browser_main_loop.

Although it still doesn't work with --single-process, and this is because
CollectGraphicsInfoGL never gets called.

I suppose we could check for BrowserMainLoop::UsingInProcessGpu(), and in that
case, just use GLVisualPickerGLX directly since the GL stuff would be loaded? 
Or is it even worth it to support this in --single-process?

[piman, 2016/09/26 21:13:29]

I think I'm ok if we punt on --single-process.
Directly using GLVisualPickerGLX may be a bit iffy because in --single-process,
the GPU main thread is a separate thread from the UI thread. Another way is to
add a call to gpu::CollectContextGraphicsInfo in InProcessGpuThread and pass the
GpuInfo that to the in-process GpuChildThread constructor.

+      gpu_info_.software_rendering || card_blacklisted_,
+      gpu_info_.system_visual, gpu_info_.rgba_visual);
+#endif
   observer_list_->Notify(FROM_HERE, &GpuDataManagerObserver::OnGpuInfoUpdate);
 }