Add OzoneGLImpl interface.

ui/ozone/public/surface_factory_ozone.h

Index: ui/ozone/public/surface_factory_ozone.h
diff --git a/ui/ozone/public/surface_factory_ozone.h b/ui/ozone/public/surface_factory_ozone.h
index 0ace5bfb9cce8036054ee97f209aca2cd4881a74..dade826f6f58dceb9f1d1d248d31ca795ca54626 100644
--- a/ui/ozone/public/surface_factory_ozone.h
+++ b/ui/ozone/public/surface_factory_ozone.h
@@ -21,6 +21,7 @@
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface.h"
 #include "ui/ozone/ozone_base_export.h"
+#include "ui/ozone/public/gl_ozone.h"
 #include "ui/ozone/public/native_pixmap.h"
 
 namespace ui {
@@ -43,11 +44,8 @@ class SurfaceOzoneCanvas;
 // 1) Accelerated Drawing (GL path):
 //
 // The following functions are specific to GL:
-//  - GetNativeDisplay (EGL only)
-//  - LoadEGLGLES2Bindings (EGL only)
-//  - CreateViewGLSurface (all GL implementations)
-//  - CreateSurfacelessViewGLSurface (EGL only)
-//  - CreateOffscreenGLSurface (all GL implementations)
+//  - GetAllowedGLImplementations
+//  - GetOzoneGLementation (along with the associated GLOzone)
 //
 // 2) Software Drawing (Skia):
 //
@@ -61,26 +59,28 @@ class SurfaceOzoneCanvas;
 // modes (See comments bellow for descriptions).
 class OZONE_BASE_EXPORT SurfaceFactoryOzone {
  public:
-  // Returns native platform display handle. This is used to obtain the EGL
-  // display connection for the native display.
+  // Returns a list of allowed GL implementations. The default implementation
+  // will be the first item.
+  virtual std::vector<gl::GLImplementation> GetAllowedGLImplementations();

[rjkroege, 2016/08/26 19:55:53]

How hard to you think that it would be move this into GLOzone?

[kylechar, 2016/08/29 15:38:15]

Not super hard but I don't think it's worth it. This method can't just be moved
into GLOzone as there will be potentially many GLOzone instances for each Ozone
platform. Each GLOzone implements one (or maybe multiple, see the
gl_factory_mac.cc..) of the GL implementation enums. If we knew what
GLImplementation corresponded to what GLOzone object then we can create a lookup
table of sorts.

I originally coded it so that each GLOzone has a method that returns the
GLImplementation it is for. SurfaceFactoryOzone then builds an
unordered_map<GLImplementation, GLOzone> based on that and can generate a list
of GLImplementations from that. It adds a bunch of a complexity to save a tiny
bit of boilerplate for each Ozone platform, so I scrapped it in favour of this.

+
+  // Returns the GLOzone to use for the specified GL implementation, or null if
+  // GL implementation doesn't exist.
+  virtual GLOzone* GetGLOzone(gl::GLImplementation implemenation);
+
+  // DEPRECATED(kylechar): Implement GLOzoneEGL instead.
   virtual intptr_t GetNativeDisplay();
 
-  // Creates a GL surface that renders directly to a view for the specified GL
-  // implementation.
+  // DEPRECATED(kylechar): Implement GLOzone instead.
   virtual scoped_refptr<gl::GLSurface> CreateViewGLSurface(
       gl::GLImplementation implementation,
       gfx::AcceleratedWidget widget);
 
-  // Creates a GL surface that renders directly into a window with surfaceless
-  // semantics for the specified GL implementation. The surface is not backed
-  // by any buffers and is used for overlay-only displays. This will return
-  // nullptr if surfaceless mode unsupported.
+  // DEPRECATED(kylechar): Implement GLOzone instead.
   virtual scoped_refptr<gl::GLSurface> CreateSurfacelessViewGLSurface(
       gl::GLImplementation implementation,
       gfx::AcceleratedWidget widget);
 
-  // Creates a GL surface used for offscreen rendering for the specified GL
-  // implementation.
+  // DEPRECATED(kylechar): Implement GLOzone instead.
   virtual scoped_refptr<gl::GLSurface> CreateOffscreenGLSurface(
       gl::GLImplementation implementation,
       const gfx::Size& size);
@@ -92,7 +92,7 @@ class OZONE_BASE_EXPORT SurfaceFactoryOzone {
   virtual std::unique_ptr<SurfaceOzoneCanvas> CreateCanvasForWidget(
       gfx::AcceleratedWidget widget);
 
-  // Sets up GL bindings for the native surface.
+  // DEPRECATED(kylechar): Implement GLOzoneEGL instead.
   virtual bool LoadEGLGLES2Bindings();
 
   // Returns all scanout formats for |widget| representing a particular display