Omnibox - Make Omnibox Extensions Ignore Stop() Calls Due to User Idleness

components/omnibox/autocomplete_provider.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_H_
 #define COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
@@ skipping 133 matching lines @@
   // tracking its matches for this query and whether it is done processing the
   // query.  When new matches are available or the provider finishes, it
   // calls the controller's OnProviderUpdate() method.  The controller can then
   // get the new matches using the provider's accessors.
   // Exception: Matches available immediately after starting the query (that
   // is, synchronously) do not cause any notifications to be sent.  The
   // controller is expected to check for these without prompting (since
   // otherwise, starting each provider running would result in a flurry of
   // notifications).
   //
-  // Once Stop() has been called, no more notifications should be sent.
+  // Once Stop() has been called, usually no more notifications should be sent.
+  // (See comments on Stop() below.)
   //
   // |minimal_changes| is an optimization that lets the provider do less work
   // when the |input|'s text hasn't changed.  See the body of
   // OmniboxPopupModel::StartAutocomplete().
   //
   // |called_due_to_focus| is true when Start() is being called in response to
   // the omnibox being focused, instead of due to e.g. user input changes.  Most
   // providers should not provide matches in this case.  Providers which want to
   // display matches on focus can use this flag to know when they can do so.
   virtual void Start(const AutocompleteInput& input,
                      bool minimal_changes,
                      bool called_due_to_focus) = 0;
 
-  // Called when a provider must not make any more callbacks for the current
-  // query. This will be called regardless of whether the provider is already
-  // done.  If the provider caches any results, it should clear the cache based
-  // on the value of |clear_cached_results|.
-  virtual void Stop(bool clear_cached_results);
+  // Advises the provider to stop processing.  This may be called even if the
+  // provider is already done.  If the provider caches any results, it should
+  // clear the cache based on the value of |clear_cached_results|.  Normally,
+  // once this is called, the provider should not send more notifications to
+  // the controller.
+  //
+  // If |user_inactivity_timer| is true, Stop() is being called because it's
+  // been a long time since the user started the current query, and returning
+  // further asynchronous results would normally just be disruptive.  Most
+  // providers should still stop processing in this case, but continuing is
+  // legal if there's a good reason the user is likely to want even long-
+  // delayed asynchronous results, e.g. the user has explicitly invoked a
+  // keyword extension and the extension is still processing the request.
+  virtual void Stop(bool clear_cached_results,
+                    bool due_to_user_inactivity);
 
   // Returns the enum equivalent to the name of this provider.
   // TODO(derat): Make metrics use AutocompleteProvider::Type directly, or at
   // least move this method to the metrics directory.
   metrics::OmniboxEventProto_ProviderType AsOmniboxEventProviderType() const;
 
   // Called to delete a match and the backing data that produced it.  This
   // match should not appear again in this or future queries.  This can only be
   // called for matches the provider marks as deletable.  This should only be
   // called when no query is running.
@@ skipping 63 matching lines @@
   ACMatches matches_;
   bool done_;
 
   Type type_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AutocompleteProvider);
 };
 
 #endif  // COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_H_