gl: Move platform-specific EGL code into separate files

ui/gl/gl_surface_x11.cc

Index: ui/gl/gl_surface_x11.cc
diff --git a/ui/gl/gl_surface_x11.cc b/ui/gl/gl_surface_x11.cc
index 74ad999e2b2f5b1e8997e4e8537df79f1e989938..113792fb33a583596416876c8802eb071f828412 100644
--- a/ui/gl/gl_surface_x11.cc
+++ b/ui/gl/gl_surface_x11.cc
@@ -19,6 +19,14 @@
 
 namespace gfx {
 
+namespace {
+
+EGLNativeDisplayType GetEGLDisplay() {
+  return base::MessagePumpForUI::GetDefaultXDisplay();
+}
+
+}  // namesapce
+
 // This OSMesa GL surface can use XLib to swap the contents of the buffer to a
 // view.
 class NativeViewGLSurfaceOSMesa : public GLSurfaceOSMesa {
@@ -64,7 +72,7 @@ bool GLSurface::InitializeOneOffInternal() {
       }
       break;
     case kGLImplementationEGLGLES2:
-      if (!GLSurfaceEGL::InitializeOneOff()) {
+      if (!GLSurfaceEGL::InitializeOneOff(GetEGLDisplay())) {
         LOG(ERROR) << "GLSurfaceEGL::InitializeOneOff failed.";
         return false;
       }