Base: cleanup for base.dll. Move base_switches back to the

base/base.gypi

Index: base/base.gypi
===================================================================
--- base/base.gypi	(revision 86133)
+++ base/base.gypi	(working copy)
@@ -34,6 +34,8 @@
           'base_paths_linux.cc',
           'base_paths_win.cc',
           'base_paths_win.h',
+          'base_switches.cc',
+          'base_switches.h',
           'basictypes.h',
           'bind.h',
           'bind_helpers.h',
@@ -438,9 +440,6 @@
         '../third_party/modp_b64/modp_b64.gyp:modp_b64',
         'third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
       ],
-      'export_dependent_settings': [
-        'third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
-      ],
       # TODO(gregoryd): direct_dependent_settings should be shared with the
       #  64-bit target, but it doesn't work due to a bug in gyp
       'direct_dependent_settings': {
@@ -536,7 +535,7 @@
         [ 'component=="shared_library"', {
           'defines': [
             'BASE_DLL',
-            'BASE_IMPLEMENTATION=1',
+            'BASE_IMPLEMENTATION',
           ],
           'conditions': [
             ['OS=="win"', {