Added image and button to privet notification

Added image to privet notification and button that goes to devices page.

BUG=245385

Review URL: https://chromiumcodereview.appspot.com/22859018

git-svn-id: http://src.chromium.org/svn/trunk/src/build@219645 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

common.gypi

@@ -1625,6 +1625,9 @@
       ['enable_webrtc==1', {
         'grit_defines': ['-D', 'enable_webrtc'],
       }],
+      ['enable_mdns==1', {
+        'grit_defines': ['-D', 'enable_mdns'],
+      }],
       ['clang_use_chrome_plugins==1 and OS!="win"', {
         'clang_chrome_plugins_flags': [
           '<!@(<(DEPTH)/tools/clang/scripts/plugin_flags.sh)'