Move last of platform dependent init from //ui/gl to //ui/gl/init.

ui/gl/BUILD.gn

 # Copyright 2014 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/linux/pkg_config.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 use_egl = is_win || is_android || is_linux
 use_glx = use_x11
@@ skipping 69 matching lines @@
     "gl_image_memory.cc",
     "gl_image_memory.h",
     "gl_image_ref_counted_memory.cc",
     "gl_image_ref_counted_memory.h",
     "gl_image_shared_memory.cc",
     "gl_image_shared_memory.h",
     "gl_image_stub.cc",
     "gl_image_stub.h",
     "gl_implementation.cc",
     "gl_implementation.h",
-    "gl_implementation_android.cc",
-    "gl_implementation_mac.cc",
-    "gl_implementation_win.cc",
     "gl_osmesa_api_implementation.cc",
     "gl_osmesa_api_implementation.h",
     "gl_share_group.cc",
     "gl_share_group.h",
     "gl_state_restorer.cc",
     "gl_state_restorer.h",
     "gl_stub_api.cc",
     "gl_stub_api.h",
     "gl_stub_api_base.h",
     "gl_stub_autogen_gl.cc",
@@ skipping 65 matching lines @@
     ]
   }
   if (is_android || is_linux) {
     sources += [
       "gl_implementation_osmesa.cc",
       "gl_implementation_osmesa.h",
     ]
   }
   if (use_x11) {
     sources += [
-      "gl_implementation_x11.cc",
       "gl_surface_egl_x11.cc",
       "gl_surface_egl_x11.h",
       "gl_surface_osmesa_x11.cc",
       "gl_surface_osmesa_x11.h",
     ]
 
     data_deps = [
       "//third_party/angle:libEGL",
       "//third_party/angle:libGLESv2",
     ]
   }
-  if (use_ozone) {
-    sources += [ "gl_implementation_ozone.cc" ]
-  }
   if (use_glx) {
     sources += [
       "gl_bindings_autogen_glx.cc",
       "gl_bindings_autogen_glx.h",
       "gl_context_glx.cc",
       "gl_context_glx.h",
       "gl_glx_api_implementation.cc",
       "gl_glx_api_implementation.h",
       "gl_image_glx.cc",
       "gl_image_glx.h",
@@ skipping 198 matching lines @@
     sources = [
       "../android/java/src/org/chromium/ui/gl/SurfaceTextureListener.java",
       "../android/java/src/org/chromium/ui/gl/SurfaceTexturePlatformWrapper.java",
     ]
     public_deps = [
       ":surface_jni_headers",
     ]
     jni_package = "ui/gl"
   }
 }