Remove windows/mac/ios specific code from //ui

ui/gl/BUILD.gn

Index: ui/gl/BUILD.gn
diff --git a/ui/gl/BUILD.gn b/ui/gl/BUILD.gn
index ae1132e06f43a540ed2e674dd79a2d13f947a07b..29bed3187bb09e1fff62d00d3185f932b077cede 100644
--- a/ui/gl/BUILD.gn
+++ b/ui/gl/BUILD.gn
@@ -26,8 +26,12 @@ component("gl") {
     "android/surface_texture.h",
     "android/surface_texture_listener.cc",
     "android/surface_texture_listener.h",
+    "egl_util.cc",
+    "egl_util.h",
     "gl_bindings.cc",
     "gl_bindings.h",
+    "gl_bindings_autogen_egl.cc",
+    "gl_bindings_autogen_egl.h",
     "gl_bindings_autogen_gl.cc",
     "gl_bindings_autogen_gl.h",
     "gl_bindings_autogen_osmesa.cc",
@@ -37,6 +41,8 @@ component("gl") {
     "gl_context.cc",
     "gl_context.h",
     "gl_context_android.cc",
+    "gl_context_egl.cc",
+    "gl_context_egl.h",
     "gl_context_mac.mm",
     "gl_context_osmesa.cc",
     "gl_context_osmesa.h",
@@ -53,11 +59,15 @@ component("gl") {
     "gl_fence.h",
     "gl_fence_arb.cc",
     "gl_fence_arb.h",
+    "gl_fence_egl.cc",
+    "gl_fence_egl.h",
     "gl_fence_nv.cc",
     "gl_fence_nv.h",
     "gl_gl_api_implementation.cc",
     "gl_gl_api_implementation.h",
     "gl_image.h",
+    "gl_image_egl.cc",
+    "gl_image_egl.h",
     "gl_image_memory.cc",
     "gl_image_memory.h",
     "gl_image_ref_counted_memory.cc",
@@ -80,6 +90,8 @@ component("gl") {
     "gl_surface.cc",
     "gl_surface.h",
     "gl_surface_android.cc",
+    "gl_surface_egl.cc",
+    "gl_surface_egl.h",
     "gl_surface_mac.cc",
     "gl_surface_osmesa.cc",
     "gl_surface_osmesa.h",
@@ -125,22 +137,6 @@ component("gl") {
     "//ui/gfx/geometry",
   ]
 
-  if (is_win || is_android || is_linux) {
-    sources += [
-      "egl_util.cc",
-      "egl_util.h",
-      "gl_bindings_autogen_egl.cc",
-      "gl_bindings_autogen_egl.h",
-      "gl_context_egl.cc",
-      "gl_context_egl.h",
-      "gl_fence_egl.cc",
-      "gl_fence_egl.h",
-      "gl_image_egl.cc",
-      "gl_image_egl.h",
-      "gl_surface_egl.cc",
-      "gl_surface_egl.h",
-    ]
-  }
   if (is_android || is_linux) {
     sources += [
       "gl_implementation_osmesa.cc",
@@ -181,42 +177,6 @@ component("gl") {
 
     deps += [ "//ui/gfx/x" ]
   }
-  if (is_win) {
-    sources += [
-      "angle_platform_impl.cc",
-      "angle_platform_impl.h",
-      "gl_bindings_autogen_wgl.cc",
-      "gl_bindings_autogen_wgl.h",
-      "gl_context_wgl.cc",
-      "gl_context_wgl.h",
-      "gl_egl_api_implementation.cc",
-      "gl_egl_api_implementation.h",
-      "gl_surface_wgl.cc",
-      "gl_surface_wgl.h",
-      "gl_wgl_api_implementation.cc",
-      "gl_wgl_api_implementation.h",
-    ]
-
-    libs = [ "dwmapi.lib" ]
-    ldflags = [ "/DELAYLOAD:dwmapi.dll" ]
-  }
-  if (is_mac) {
-    sources += [
-      "gl_context_cgl.cc",
-      "gl_context_cgl.h",
-      "gl_fence_apple.cc",
-      "gl_fence_apple.h",
-      "gl_image_io_surface.cc",
-      "gl_image_io_surface.h",
-      "scoped_cgl.cc",
-      "scoped_cgl.h",
-    ]
-
-    libs = [
-      "IOSurface.framework",
-      "OpenGL.framework",
-    ]
-  }
   if (is_android) {
     sources += [
       "gl_egl_api_implementation.cc",