Change the separator for chhanel id to a / for consistency.

chrome/browser/extensions/api/push_messaging/push_messaging_api.cc

Index: chrome/browser/extensions/api/push_messaging/push_messaging_api.cc
===================================================================
--- chrome/browser/extensions/api/push_messaging/push_messaging_api.cc	(revision 153336)
+++ chrome/browser/extensions/api/push_messaging/push_messaging_api.cc	(working copy)
@@ -34,6 +34,10 @@
 
 using content::BrowserThread;
 
+namespace {
+static const char kChannelIdSeparator[] = "/";
+}
+
 namespace extensions {
 
 namespace glue = api::experimental_push_messaging;
@@ -165,7 +169,7 @@
   // channel ID here.
   std::string channel_id(gaia_id);
   if (!gaia_id.empty()) {
-    channel_id += ".";
+    channel_id += kChannelIdSeparator;
     channel_id += extension_id();
   }