Move common cloud print methods from service/cloud_print to common/cloud_print.

chrome/service/cloud_print/cloud_print_proxy_backend.h

Index: chrome/service/cloud_print/cloud_print_proxy_backend.h
diff --git a/chrome/service/cloud_print/cloud_print_proxy_backend.h b/chrome/service/cloud_print/cloud_print_proxy_backend.h
index a78ce3bcd9840900f654bf89652610f3ff7de7d5..2da43152290538bb7b2fa69989deb6d73fbdca01 100644
--- a/chrome/service/cloud_print/cloud_print_proxy_backend.h
+++ b/chrome/service/cloud_print/cloud_print_proxy_backend.h
@@ -20,6 +20,8 @@ namespace gaia {
 struct OAuthClientInfo;
 }
 
+namespace cloud_print {
+
 // CloudPrintProxyFrontend is the interface used by CloudPrintProxyBackend to
 // communicate with the entity that created it and, presumably, is interested in
 // cloud print proxy related activity.
@@ -102,4 +104,6 @@ class CloudPrintProxyBackend {
   DISALLOW_COPY_AND_ASSIGN(CloudPrintProxyBackend);
 };
 
+}  // namespace cloud_print
+
 #endif  // CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_PROXY_BACKEND_H_