Support GrabWindowSnapshot with no g_browser_process

ui/ui.gyp

Index: ui/ui.gyp
diff --git a/ui/ui.gyp b/ui/ui.gyp
index ef2b48ac4241820b1ed27512d5ab83c53e4a788e..754c9a707c71253358eff78c5e492b8f1504397d 100644
--- a/ui/ui.gyp
+++ b/ui/ui.gyp
@@ -464,6 +464,10 @@
         'ui_controls/ui_controls_gtk.cc',
         'ui_controls/ui_controls_mac.mm',
         'ui_controls/ui_controls_win.cc',
+        'window_snapshot/window_snapshot_aura.cc',
+        'window_snapshot/window_snapshot_gtk.cc',
+        'window_snapshot/window_snapshot_mac.mm',
+        'window_snapshot/window_snapshot_win.cc',
       ],
       'conditions': [
         # TODO(asvitkine): Switch all platforms to use canvas_skia.cc.
@@ -500,6 +504,7 @@
             ['exclude', 'base/x/work_area_watcher_x.cc'],
             ['exclude', 'base/x/work_area_watcher_x.h'],
             ['exclude', 'ui_controls_win.cc'],
+            ['exclude', 'window_snapshot/window_snapshot_win.cc'],
            ],
         }, {  # use_aura!=1
           'sources!': [
@@ -548,7 +553,7 @@
           ],
           'link_settings': {
             'libraries': [
-              '-lXcursor',  # For XCursor* function calls in x11_util.cc. 
+              '-lXcursor',  # For XCursor* function calls in x11_util.cc.
               '-lXrender',  # For XRender* function calls in x11_util.cc.
             ],
           },