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

ui/base/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/ui.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
 }
@@ skipping 27 matching lines @@
     "//base:i18n",
     "//third_party/icu",
     "//url",
   ]
 
   if (is_linux) {
     configs += [ "//build/config/linux:fontconfig" ]
   }
 
   libs = []
-  if (is_win) {
-    cflags = [
-      "/wd4267",  # TODO(jschuh): C4267: http://crbug.com/167187 size_t -> int.
-      "/wd4324",  # Structure was padded due to __declspec(align()), which is
-                  # uninteresting.
-    ]
-    ldflags = [
-      "/DELAYLOAD:d2d1.dll",
-      "/DELAYLOAD:d3d10_1.dll",
-      "/DELAYLOAD:dwmapi.dll",
-    ]
-    libs += [
-      "d2d1.lib",
-      "d3d10_1.lib",
-      "dwmapi.lib",
-      "imm32.lib",
-      "d2d1.lib",
-      "dwmapi.lib",
-      "oleacc.lib",
-    ]
-  }
-
-  if (is_mac) {
-    deps += [ "//third_party/mozilla" ]
-
-    libs += [
-      "Accelerate.framework",
-      "AudioUnit.framework",
-      "CoreVideo.framework",
-    ]
-  }
 
   if (use_x11) {
     #'all_dependent_settings': {
     #'ldflags': [
     #'-L<(PRODUCT_DIR)',
     #],
     #},
     configs += [ "//build/config/linux:x11" ]
   }
 
@@ skipping 51 matching lines @@
         "//testing/gmock",
         "//testing/gtest",
         "//third_party/icu",
         "//ui/base",
         "//ui/events:events_base",
         "//ui/events:test_support",
         "//ui/gfx:test_support",
         "//url",
       ]
 
-      if (is_win) {
-        ldflags = [
-          "/DELAYLOAD:d2d1.dll",
-          "/DELAYLOAD:d3d10_1.dll",
-        ]
-        libs = [
-          "d2d1.lib",
-          "d3d10_1.lib",
-          "imm32.lib",
-          "oleacc.lib",
-        ]
-
-        # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
-        cflags = [ "/wd4267" ]
-      }
-
       if (is_android) {
         deps += [
           #"testing/android/native_test.gyp:native_test_native_code"  TODO(GYP)
         ]
       }
 
       if (use_x11) {
         configs += [ "//build/config/linux:x11" ]
 
         deps += [ "//ui/gfx/x" ]
 
         datadeps = [
           "//tools/xdisplaycheck",
         ]
       }
 
-      if (!is_win) {
-        sources -= [ "view_prop_unittest.cc" ]
-      }
-
-      if (is_mac) {
-        deps += [
-          "//third_party/mozilla",
-          #'ui_unittests_bundle',  TODO(GYP)
-        ]
-      }
+      sources -= [ "view_prop_unittest.cc" ]
 
       if (is_chromeos) {
         sources += [ "../chromeos/touch_exploration_controller_unittest.cc" ]
         deps += [
           "//chromeos",
           "//ui/aura:test_support",
           "//ui/events:gesture_detection",
           "//ui/chromeos:ui_chromeos",
         ]
       }
     }
   }
 }
 # TODO(GYP) Mac (ui_unittest_bundle) and Android (ui_unittests_apk).