Disable ProfileKeyedServices on import process by default.

chrome/browser/profiles/profile_keyed_base_factory.h

Index: chrome/browser/profiles/profile_keyed_base_factory.h
diff --git a/chrome/browser/profiles/profile_keyed_base_factory.h b/chrome/browser/profiles/profile_keyed_base_factory.h
index 3d9899f1d5641f5779ebe8d6e1a7a1a9270c319b..bfcb054ca0794d536e27f2e7d3bf139ace4d0d86 100644
--- a/chrome/browser/profiles/profile_keyed_base_factory.h
+++ b/chrome/browser/profiles/profile_keyed_base_factory.h
@@ -72,6 +72,14 @@ class ProfileKeyedBaseFactory : public base::NonThreadSafe {
   // services they use.)
   virtual bool ServiceIsNULLWhileTesting() const;
 
+  // By default, we do not create any services on the import process. Any
+  // services that are required to perform an import should override this method
+  // and return |false|. Note that any services created on the import process
+  // may run in parallel with another instance of the service running in the
+  // main browser process, so care must be taken to avoid conflicting use of
+  // non-shareable resources like DB files.
+  virtual bool ServiceIsNULLOnImportProcess() const;
+
   // Interface for people building a type of ProfileKeyedFactory: -------------
 
   // A helper object actually listens for notifications about Profile