content: Add ContextProviderFactory to create a render ContextProvider.

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 8103470dabc4d39a3395112eb769ac105ab5a374..33840147ec776c4bbe067537644281b9547c8c3e 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -111,10 +111,12 @@
 #include "content/browser/android/browser_surface_texture_manager.h"
 #include "content/browser/android/tracing_controller_android.h"
 #include "content/browser/media/android/browser_media_player_manager.h"
+#include "content/browser/renderer_host/context_provider_factory_impl_android.h"
 #include "content/browser/screen_orientation/screen_orientation_delegate_android.h"
 #include "content/public/browser/screen_orientation_provider.h"
 #include "gpu/ipc/client/android/in_process_surface_texture_manager.h"
 #include "media/base/android/media_client_android.h"
+#include "ui/android/context_provider_factory.h"

[no sievers, 2016/07/29 19:14:30]

nit: not needed for base class

 #include "ui/gl/gl_surface.h"
 #endif
 
@@ -1234,6 +1236,8 @@ int BrowserMainLoop::BrowserThreadsStarted() {
   established_gpu_channel = false;
   always_uses_gpu = ShouldStartGpuProcessOnBrowserStartup();
   BrowserGpuChannelHostFactory::Initialize(established_gpu_channel);
+  ui::ContextProviderFactory::SetInstance(
+      ContextProviderFactoryImpl::GetInstance());

[no sievers, 2016/07/29 19:14:30]

do we leak this?

Can you unset it somewhere around where we also do
ImageTransportFactory::Terminate() in this file?

[Khushal, 2016/07/29 21:30:55]

The singleton would still remain with the ContextProviderFactoryImpl right? I
was following a pattern similar to DiscardableMemoryAllocator.

[no sievers, 2016/07/29 21:42:41]

sounds good

 #elif defined(USE_AURA) || defined(OS_MACOSX)
   established_gpu_channel = true;
   if (!GpuDataManagerImpl::GetInstance()->CanUseGpuBrowserCompositor() ||