Refactored the CloudPolicyProvider so that it becomes initialized once and stays initialized.

chrome/browser/policy/user_policy_disk_cache.cc

Index: chrome/browser/policy/user_policy_disk_cache.cc
diff --git a/chrome/browser/policy/user_policy_disk_cache.cc b/chrome/browser/policy/user_policy_disk_cache.cc
index 1aa19a5c8c39b874ad7a9dbf465782f90c6644f9..4b0883662b7c78d75330d25cf62f960b1a217ae3 100644
--- a/chrome/browser/policy/user_policy_disk_cache.cc
+++ b/chrome/browser/policy/user_policy_disk_cache.cc
@@ -46,9 +46,10 @@ UserPolicyDiskCache::UserPolicyDiskCache(
 
 void UserPolicyDiskCache::Load() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  BrowserThread::PostTask(
+  bool ret = BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&UserPolicyDiskCache::LoadOnFileThread, this));
+  DCHECK(ret);
 }
 
 void UserPolicyDiskCache::Store(