Split GL binding init into core and extension part

ui/gfx/gl/gl_implementation_mac.cc

Index: ui/gfx/gl/gl_implementation_mac.cc
diff --git a/ui/gfx/gl/gl_implementation_mac.cc b/ui/gfx/gl/gl_implementation_mac.cc
index 780f6a7cf5117ac1ec61cda331832f6cf8b1dbb2..24d2c4d8902ccd9839735737162de42fe2ceb337 100644
--- a/ui/gfx/gl/gl_implementation_mac.cc
+++ b/ui/gfx/gl/gl_implementation_mac.cc
@@ -96,6 +96,26 @@ bool InitializeGLBindings(GLImplementation implementation) {
   return true;
 }
 
+bool InitializeGLExtensionBindings(GLImplementation implementation,
+    GLContext* context) {
+  switch (implementation) {
+    case kGLImplementationOSMesaGL:
+      InitializeGLExtensionBindingsGL(context);
+      InitializeGLExtensionBindingsOSMESA(context);
+      break;
+    case kGLImplementationDesktopGL:
+      InitializeGLExtensionBindingsGL(context);
+      break;
+    case kGLImplementationMockGL:
+      InitializeGLExtensionBindingsGL(context);
+      break;
+    default:
+      return false;
+  }
+
+  return true;
+}
+
 void InitializeDebugGLBindings() {
   InitializeDebugGLBindingsGL();
   InitializeDebugGLBindingsOSMESA();