Add API in developerPrivate to allow/ disallow incognito mode.

chrome/browser/extensions/api/developer_private/developer_private_api.h

Index: chrome/browser/extensions/api/developer_private/developer_private_api.h
diff --git a/chrome/browser/extensions/api/developer_private/developer_private_api.h b/chrome/browser/extensions/api/developer_private/developer_private_api.h
index 980185957f7d76531246f30f779727f52131645d..73d98c87ea4bcfa81c4986af0667aa50004833dd 100644
--- a/chrome/browser/extensions/api/developer_private/developer_private_api.h
+++ b/chrome/browser/extensions/api/developer_private/developer_private_api.h
@@ -163,6 +163,18 @@ class DeveloperPrivateAllowFileAccessFunction : public SyncExtensionFunction {
   virtual bool RunImpl() OVERRIDE;
 };
 
+class DeveloperPrivateAllowIncognitoFunction : public SyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("developerPrivate.allowIncognito",
+                             DEVELOPERPRIVATE_ALLOWINCOGNITO);
+
+ protected:
+  virtual ~DeveloperPrivateAllowIncognitoFunction();
+
+  // ExtensionFunction:
+  virtual bool RunImpl() OVERRIDE;
+};
+
 class DeveloperPrivateReloadFunction : public SyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("developerPrivate.reload",