Instant: Use only one hidden WebContents per profile.

chrome/common/omnibox_types.h

+// Copyright 2013 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 CHROME_COMMON_OMNIBOX_TYPES_H_
+#define CHROME_COMMON_OMNIBOX_TYPES_H_
+
+// Omnibox focus state.
+enum OmniboxFocusState {
+  // Not focused.
+  OMNIBOX_FOCUS_NONE,
+
+  // Visibly focused.
+  OMNIBOX_FOCUS_VISIBLE,
+
+  // Invisibly focused, i.e. focused with a hidden caret.
+  OMNIBOX_FOCUS_INVISIBLE,
+};
+
+// Reasons why the Omnibox focus state could change.
+enum OmniboxFocusChangeReason {
+  // Includes any explicit changes to focus. (e.g. user clicking to change
+  // focus, user tabbing to change focus, any explicit calls to SetFocus, etc.)
+  OMNIBOX_FOCUS_CHANGE_EXPLICIT,
+
+  // Focus changed to restore state from a tab the user switched to.
+  OMNIBOX_FOCUS_CHANGE_TAB_SWITCH,
+
+  // Focus changed because user started typing. This only happens when focus
+  // state is INVISIBLE (and this results in a change to VISIBLE).
+  OMNIBOX_FOCUS_CHANGE_TYPING,
+};
+
+#endif  // CHROME_COMMON_OMNIBOX_TYPES_H_