Persist sessionStorage on disk.

content/public/browser/browser_context.h

Index: content/public/browser/browser_context.h
diff --git a/content/public/browser/browser_context.h b/content/public/browser/browser_context.h
index 487246aa0375a8e1542c800ee56a25e3667efc91..801e7ead669455f9bd3f587bfb6421d1e0c4e1d9 100644
--- a/content/public/browser/browser_context.h
+++ b/content/public/browser/browser_context.h
@@ -73,6 +73,7 @@ class CONTENT_EXPORT BrowserContext : public base::SupportsUserData {
   // Tells the HTML5 objects on this context to purge any uneeded memory.
   static void PurgeMemory(BrowserContext* browser_context);
 
+  BrowserContext();
   virtual ~BrowserContext();
 
   // Returns the path of the directory where this context's data is stored.
@@ -123,6 +124,19 @@ class CONTENT_EXPORT BrowserContext : public base::SupportsUserData {
 
   // Returns a special storage policy implementation, or NULL.
   virtual quota::SpecialStoragePolicy* GetSpecialStoragePolicy() = 0;
+
+  // Controls if sessionStorage should be saved on disk. This function must be
+  // called before any of the services are requested (see static getters
+  // above). Even if |save_session_storage_on_disk| is true, sessionStorage
+  // won't be saved if |IsOffTheRecord| returns true.
+  void SetSaveSessionStorageOnDisk(bool save_session_storage_on_disk);
+
+  bool save_session_storage_on_disk() const {
+    return save_session_storage_on_disk_;
+  }
+
+private:
+  bool save_session_storage_on_disk_;
 };
 
 }  // namespace content