Implement GLX for Ozone X11.

ui/ozone/platform/x11/ozone_platform_x11.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/ozone/platform/x11/ozone_platform_x11.h"
 
 #include <X11/Xlib.h>
 
 #include <utility>
 
@@ skipping 74 matching lines @@
     window->Create();
     return std::move(window);
   }
 
   scoped_ptr<NativeDisplayDelegate> CreateNativeDisplayDelegate() override {
     return make_scoped_ptr(new NativeDisplayDelegateOzone());
   }
 
   void InitializeUI() override {
     window_manager_.reset(new X11WindowManagerOzone);
-    event_source_.reset(new X11EventSourceLibevent(gfx::GetXDisplay()));
+    if (!event_source_)
+      event_source_.reset(new X11EventSourceLibevent(gfx::GetXDisplay()));
     overlay_manager_.reset(new StubOverlayManager());
     input_controller_ = CreateStubInputController();
     cursor_factory_ozone_.reset(new X11CursorFactoryOzone());
     gpu_platform_support_host_.reset(CreateStubGpuPlatformSupportHost());
   }
 
   void InitializeGPU() override {
+    if (!event_source_)

[sadrul, 2016/04/19 14:49:49]

The null-check here (and above) implies we may be calling InitializeUI() and
InitializeGPU() on the same OzonePlatform instance. Is that expected?

[kylechar, 2016/04/19 16:00:20]

Yep. In MUS they are both in the same process.

[sadrul, 2016/04/19 16:13:37]

Oh, that's interesting.

PlatformEventSource (and related things) are not thread-safe. So if both the UI
and GPU threads in mus are trying to do things (e.g. add/remove observers), then
that's going to pose a problem. Can we send the expose events to the GPU side
via some other (more explicit, mus/ozone-specific) mechanism?

+      event_source_.reset(new X11EventSourceLibevent(gfx::GetXDisplay()));
     surface_factory_ozone_.reset(new X11SurfaceFactory());
     gpu_platform_support_.reset(CreateStubGpuPlatformSupport());
   }
 
  private:
   // Objects in the Browser process.
   scoped_ptr<X11WindowManagerOzone> window_manager_;
-  scoped_ptr<X11EventSourceLibevent> event_source_;
   scoped_ptr<OverlayManagerOzone> overlay_manager_;
   scoped_ptr<InputController> input_controller_;
   scoped_ptr<X11CursorFactoryOzone> cursor_factory_ozone_;
   scoped_ptr<GpuPlatformSupportHost> gpu_platform_support_host_;
 
   // Objects in the GPU process.
   scoped_ptr<X11SurfaceFactory> surface_factory_ozone_;
   scoped_ptr<GpuPlatformSupport> gpu_platform_support_;
 
+  // Objects in both Browser and GPU process.
+  scoped_ptr<X11EventSourceLibevent> event_source_;
+
   DISALLOW_COPY_AND_ASSIGN(OzonePlatformX11);
 };
 
 }  // namespace
 
 OzonePlatform* CreateOzonePlatformX11() {
   return new OzonePlatformX11;
 }
 
 }  // namespace ui