Move GLContext creation from //ui/gl to //ui/gl/init.

ui/gl/init/BUILD.gn

 # 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.
 
 import("//build/config/ui.gni")
 
 component("init") {
   output_name = "gl_init"
 
   public = [
@@ skipping 10 matching lines @@
   deps = [
     "//base",
     "//ui/gfx",
   ]
 
   public_deps = [
     "//ui/gl",
   ]
 
   if (is_android) {
-    sources += [ "gl_initializer_android.cc" ]
+    sources += [
+      "gl_factory_android.cc",
+      "gl_initializer_android.cc",
+    ]
   } else if (is_win) {
-    sources += [ "gl_initializer_win.cc" ]
+    sources += [
+      "gl_factory_win.cc",
+      "gl_initializer_win.cc",
+    ]
   } else if (is_mac) {
-    sources += [ "gl_initializer_mac.cc" ]
+    sources += [
+      "gl_factory_mac.cc",
+      "gl_initializer_mac.cc",
+    ]
 
     libs = [ "OpenGL.framework" ]
   } else if (use_x11) {
-    sources += [ "gl_initializer_x11.cc" ]
+    sources += [
+      "gl_factory_x11.cc",
+      "gl_initializer_x11.cc",
+    ]
   } else if (use_ozone) {
-    sources += [ "gl_initializer_ozone.cc" ]
+    sources += [
+      "gl_factory_ozone.cc",
+      "gl_initializer_ozone.cc",
+    ]
   }
 }