Introduce ui.dll / libui.so for the component build.

ui/ui_base.gypi

Index: ui/ui_base.gypi
===================================================================
--- ui/ui_base.gypi	(revision 91577)
+++ ui/ui_base.gypi	(working copy)
@@ -6,9 +6,9 @@
   'targets': [
     {
       'target_name': 'ui_base',
-      'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
+        '../base/base.gyp:base_static',
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         '../build/temp_gyp/googleurl.gyp:googleurl',
         '../net/net.gyp:net',
@@ -154,8 +154,8 @@
         'base/win/hwnd_util.h',
         'base/win/ime_input.cc',
         'base/win/ime_input.h',
-	'base/win/shell.cc',
-	'base/win/shell.h',
+        'base/win/shell.cc',
+        'base/win/shell.h',
         'base/win/window_impl.cc',
         'base/win/window_impl.h',
         'base/x/active_window_watcher_x.cc',
@@ -197,7 +197,10 @@
             }],
           ],
         }],
-        ['OS!="win"', {
+        ['OS=="win"', {
+          'type': '<(component)', 
+        },{  # else: OS!="win"
+          'type': 'static_library',
           'sources!': [
             'base/dragdrop/drag_source.cc',
             'base/dragdrop/drag_source.h',
@@ -212,6 +215,23 @@
             ['exclude', '^base/win/*'],
           ],
         }],
+        ['OS=="win" and component == "shared_library"', {
+          'defines': [
+            'UI_BASE_DLL',
+            'UI_BASE_IMPLEMENTATION',
+          ],
+          'msvs_disabled_warnings': [
+            4251,
+          ],
+          'direct_dependent_settings': {
+            'defines': [
+              'UI_BASE_DLL',
+            ],
+            'msvs_disabled_warnings': [
+              4251,
+            ],
+          },
+        }],
         ['OS=="mac"', {
           'link_settings': {
             'libraries': [