Not creating ClientUsageTracker for unsupported storage type.

webkit/browser/fileapi/file_system_context.cc

Index: webkit/browser/fileapi/file_system_context.cc
diff --git a/webkit/browser/fileapi/file_system_context.cc b/webkit/browser/fileapi/file_system_context.cc
index f2973d35fa2dae22c1c9bd90880c1b5c73c6df8c..6619259d2303cd9c484752aefdcfa7d4d8a6ff66 100644
--- a/webkit/browser/fileapi/file_system_context.cc
+++ b/webkit/browser/fileapi/file_system_context.cc
@@ -121,11 +121,6 @@ FileSystemContext::FileSystemContext(
       external_mount_points_(external_mount_points),
       partition_path_(partition_path),
       operation_runner_(new FileSystemOperationRunner(this)) {
-  if (quota_manager_proxy) {
-    quota_manager_proxy->RegisterClient(CreateQuotaClient(
-            this, options.is_incognito()));
-  }
-
   RegisterBackend(sandbox_backend_.get());
   RegisterBackend(isolated_backend_.get());
 
@@ -135,6 +130,12 @@ FileSystemContext::FileSystemContext(
     RegisterBackend(*iter);
   }
 
+  if (quota_manager_proxy) {
+    // Quota client assumes all backends have registered.
+    quota_manager_proxy->RegisterClient(CreateQuotaClient(
+            this, options.is_incognito()));
+  }
+
   sandbox_backend_->Initialize(this);
   isolated_backend_->Initialize(this);
   for (ScopedVector<FileSystemBackend>::const_iterator iter =
@@ -230,7 +231,8 @@ FileSystemBackend* FileSystemContext::GetFileSystemBackend(
 }
 
 bool FileSystemContext::IsSandboxFileSystem(FileSystemType type) const {
-  return GetQuotaUtil(type) != NULL;
+  FileSystemBackendMap::const_iterator found = backend_map_.find(type);
+  return found != backend_map_.end() && found->second->GetQuotaUtil();
 }
 
 const UpdateObserverList* FileSystemContext::GetUpdateObservers(