chromeos: Add support for the battery status API on chromeos.

content/content_browser.gypi

Index: content/content_browser.gypi
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 712d8882b923708b94a883e12cf83c75840e7cd0..20570cff00f89f9bc580a6df76c6159499786933 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -180,6 +180,8 @@
     'browser/appcache/appcache_frontend_proxy.h',
     'browser/appcache/chrome_appcache_service.cc',
     'browser/appcache/chrome_appcache_service.h',
+    'browser/battery_status/battery_status_message_filter.cc',
+    'browser/battery_status/battery_status_message_filter.h',
     'browser/browser_child_process_host_impl.cc',
     'browser/browser_child_process_host_impl.h',
     'browser/browser_context.cc',
@@ -846,6 +848,10 @@
         'browser/renderer_host/gtk_key_bindings_handler.cc',
         'browser/renderer_host/gtk_key_bindings_handler.h',
       ],
+    }, { # chromeos == 0
+      'sources/': [
+        ['exclude', '^browser/battery_status/'],
+      ]
     }],
     ['os_bsd==1', {
       'sources/': [