Ensure static BrowserContext methods only get called on the UI thread.

chrome/browser/browsing_data_file_system_helper.cc

Index: chrome/browser/browsing_data_file_system_helper.cc
===================================================================
--- chrome/browser/browsing_data_file_system_helper.cc	(revision 145676)
+++ chrome/browser/browsing_data_file_system_helper.cc	(working copy)
@@ -50,9 +50,9 @@
   // the FILE thread.
   void DeleteFileSystemOriginInFileThread(const GURL& origin);
 
-  // We don't own the Profile object. Clients are responsible for destroying the
-  // object when it's no longer used.
-  Profile* profile_;
+  // Keep a reference to the FileSystemContext object for the current profile
+  // for use on the FILE thread.
+  scoped_refptr<fileapi::FileSystemContext> filesystem_context_;
 
   // Holds the current list of file systems returned to the client after
   // StartFetching is called. Access to |file_system_info_| is triggered
@@ -78,9 +78,9 @@
 
 BrowsingDataFileSystemHelperImpl::BrowsingDataFileSystemHelperImpl(
     Profile* profile)
-    : profile_(profile),
+    : filesystem_context_(BrowserContext::GetFileSystemContext(profile)),
       is_fetching_(false) {
-  DCHECK(profile_);
+  DCHECK(filesystem_context_);
 }
 
 BrowsingDataFileSystemHelperImpl::~BrowsingDataFileSystemHelperImpl() {
@@ -113,16 +113,13 @@
 void BrowsingDataFileSystemHelperImpl::FetchFileSystemInfoInFileThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   scoped_ptr<fileapi::SandboxMountPointProvider::OriginEnumerator>
-      origin_enumerator(BrowserContext::GetFileSystemContext(profile_)->
+      origin_enumerator(filesystem_context_->
           sandbox_provider()->CreateOriginEnumerator());
 
-  scoped_refptr<fileapi::FileSystemContext> context =
-      BrowserContext::GetFileSystemContext(profile_);
-
   // We don't own this pointer; it's a magic singleton generated by the
   // profile's FileSystemContext. Deleting it would be a bad idea.
   fileapi::FileSystemQuotaUtil* quota_util =
-     context->GetQuotaUtil(fileapi::kFileSystemTypeTemporary);
+     filesystem_context_->GetQuotaUtil(fileapi::kFileSystemTypeTemporary);
 
   GURL current;
 
@@ -133,10 +130,10 @@
     // We can call these synchronous methods as we've already verified that
     // we're running on the FILE thread.
     int64 persistent_usage = quota_util->GetOriginUsageOnFileThread(
-        context, current,
+        filesystem_context_, current,
         fileapi::kFileSystemTypePersistent);
     int64 temporary_usage = quota_util->GetOriginUsageOnFileThread(
-        context, current,
+        filesystem_context_, current,
         fileapi::kFileSystemTypeTemporary);
     file_system_info_.push_back(
         FileSystemInfo(
@@ -165,8 +162,7 @@
 void BrowsingDataFileSystemHelperImpl::DeleteFileSystemOriginInFileThread(
     const GURL& origin) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
-  BrowserContext::GetFileSystemContext(profile_)->
-      DeleteDataForOriginOnFileThread(origin);
+  filesystem_context_->DeleteDataForOriginOnFileThread(origin);
 }
 
 }  // namespace