gl: Move platform-specific EGL code into separate files

ui/gl/gl_surface_egl.h

Index: ui/gl/gl_surface_egl.h
diff --git a/ui/gl/gl_surface_egl.h b/ui/gl/gl_surface_egl.h
index db0ebd868faee059c17c9b7b3cec44a3c8223c04..7a3acd8f305de3ed2be376f480fc4cbbc4bdcb6c 100644
--- a/ui/gl/gl_surface_egl.h
+++ b/ui/gl/gl_surface_egl.h
@@ -28,7 +28,7 @@ class GL_EXPORT GLSurfaceEGL : public GLSurface {
   // Implement GLSurface.
   virtual EGLDisplay GetDisplay() OVERRIDE;
 
-  static bool InitializeOneOff();
+  static bool InitializeOneOff(EGLNativeDisplayType native_display);
   static EGLDisplay GetHardwareDisplay();
   static EGLNativeDisplayType GetNativeDisplay();
 
@@ -38,6 +38,7 @@ class GL_EXPORT GLSurfaceEGL : public GLSurface {
   static const char* GetEGLExtensions();
   static bool HasEGLExtension(const char* name);
   static bool IsCreateContextRobustnessSupported();
+  static bool IsEGLSurfacelessContextSupported();
 
  protected:
   virtual ~GLSurfaceEGL();