Move InMemoryURLIndex Caching Operations to FILE Thread

chrome/browser/history/in_memory_url_index_types.h

Index: chrome/browser/history/in_memory_url_index_types.h
===================================================================
--- chrome/browser/history/in_memory_url_index_types.h	(revision 125078)
+++ chrome/browser/history/in_memory_url_index_types.h	(working copy)
@@ -10,6 +10,7 @@
 #include <set>
 #include <vector>
 
+#include "base/memory/ref_counted.h"
 #include "base/string16.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/browser/autocomplete/history_provider_util.h"
@@ -74,6 +75,29 @@
 };
 typedef std::vector<ScoredHistoryMatch> ScoredHistoryMatches;
 
+// RefCountedBool --------------------------------------------------------------
+
+// An implementation of RefCountedMemory that manages a bool that we use for
+// passing around success when saving our cache.
+class RefCountedBool : public RefCountedMemory {
+ public:
+  explicit RefCountedBool(bool value) : bool_(value) {}
+
+  virtual const unsigned char* front() const OVERRIDE;
+  virtual size_t size() const OVERRIDE;
+
+  bool value() { return bool_; }
+  void set_value(bool value) { bool_ = value; }
+
+ private:
+  friend class base::RefCountedThreadSafe<RefCountedBool>;
+  virtual ~RefCountedBool();
+
+  bool bool_;
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedBool);
+};
+
 // Convenience Types -----------------------------------------------------------
 
 typedef std::vector<string16> String16Vector;