Make sure the google wallet in-app payment support app is always installed.

chrome/common/extensions/extension_constants.h

Index: chrome/common/extensions/extension_constants.h
diff --git a/chrome/common/extensions/extension_constants.h b/chrome/common/extensions/extension_constants.h
index 9566f17952f28875d5bef2fad2a3f337f7fbf028..96b4106bd151cb44c11b79efbf18796f25cfd7ea 100644
--- a/chrome/common/extensions/extension_constants.h
+++ b/chrome/common/extensions/extension_constants.h
@@ -160,6 +160,9 @@ namespace extension_misc {
   // The extension id of the Youtube application.
   extern const char kYoutubeAppId[];
 
+  // The extension id of the in-app payments support application.
+  extern const char kInAppPaymentsSupportAppId[];
+
   // Note: this structure is an ASN.1 which encodes the algorithm used
   // with its parameters. This is defined in PKCS #1 v2.1 (RFC 3447).
   // It is encoding: { OID sha1WithRSAEncryption      PARAMETERS NULL }