Move a bunch of code in content\common (as well as a few left in renderer) to the content namespace.

content/common/appcache/appcache_backend_proxy.cc

Index: content/common/appcache/appcache_backend_proxy.cc
===================================================================
--- content/common/appcache/appcache_backend_proxy.cc	(revision 163290)
+++ content/common/appcache/appcache_backend_proxy.cc	(working copy)
@@ -6,6 +6,8 @@
 
 #include "content/common/appcache_messages.h"
 
+namespace content {
+
 void AppCacheBackendProxy::RegisterHost(int host_id) {
   sender_->Send(new AppCacheHostMsg_RegisterHost(host_id));
 }
@@ -74,3 +76,5 @@
     int host_id, std::vector<appcache::AppCacheResourceInfo>* resource_infos) {
   sender_->Send(new AppCacheHostMsg_GetResourceList(host_id, resource_infos));
 }
+
+}  // namespace content