Add default icon to app_host.exe, and use it in shortcuts during installation.

chrome/installer/util/google_chrome_distribution_dummy.cc

Index: chrome/installer/util/google_chrome_distribution_dummy.cc
diff --git a/chrome/installer/util/google_chrome_distribution_dummy.cc b/chrome/installer/util/google_chrome_distribution_dummy.cc
index 933c631f3b46510157ed7603d64bcbded4dd3995..2dcd70424f0fb3c87b4cc2af3f6826f1f2794ddd 100644
--- a/chrome/installer/util/google_chrome_distribution_dummy.cc
+++ b/chrome/installer/util/google_chrome_distribution_dummy.cc
@@ -116,6 +116,11 @@ string16 GoogleChromeDistribution::GetVersionKey() {
   return string16();
 }
 
+string16 GoogleChromeDistribution::GetIconFile() {
+  NOTREACHED();
+  return string16();
+}
+
 bool GoogleChromeDistribution::GetCommandExecuteImplClsid(
     string16* handler_class_uuid) {
   NOTREACHED();