Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/ui/omnibox/omnibox_edit_model.h

Index: chrome/browser/ui/omnibox/omnibox_edit_model.h
diff --git a/chrome/browser/ui/omnibox/omnibox_edit_model.h b/chrome/browser/ui/omnibox/omnibox_edit_model.h
index 6caf62f542932a94b4d3cbe564454c88cc6574c4..f8444f67bb086fe528660a87a103a257bdf3e1f8 100644
--- a/chrome/browser/ui/omnibox/omnibox_edit_model.h
+++ b/chrome/browser/ui/omnibox/omnibox_edit_model.h
@@ -37,13 +37,15 @@ class OmniboxEditModel : public AutocompleteControllerDelegate {
     State(bool user_input_in_progress,
           const string16& user_text,
           const string16& keyword,
-          bool is_keyword_hint);
+          bool is_keyword_hint,
+          bool is_caret_visible);
     ~State();
 
     bool user_input_in_progress;
     const string16 user_text;
     const string16 keyword;
     const bool is_keyword_hint;
+    const bool is_caret_visible;
   };
 
   OmniboxEditModel(OmniboxView* view,
@@ -190,6 +192,7 @@ class OmniboxEditModel : public AutocompleteControllerDelegate {
                  size_t index);
 
   bool has_focus() const { return has_focus_; }
+  bool is_caret_visible() const { return is_caret_visible_; }
 
   // Accessors for keyword-related state (see comments on keyword_ and
   // is_keyword_hint_).
@@ -213,6 +216,17 @@ class OmniboxEditModel : public AutocompleteControllerDelegate {
   // control key is down (at the time we're gaining focus).
   void OnSetFocus(bool control_down);
 
+  // Sets the visibility of the caret in the omnibox, if it has focus. The
+  // visibility of the caret is reset to visible if any of the following
+  // happens:
+  // - User starts typing in the omnibox
+  // - User clicks in the omnibox
+  // - Omnibox loses and then regains focus
+  // - SetFocus() is explicitly called again
+  // Caret visibility is tracked per-tab and updates automatically upon
+  // switching tabs.
+  void SetCaretVisibility(bool visible);
+
   // Sent before |OnKillFocus| and before the popup is closed.
   void OnWillKillFocus(gfx::NativeView view_gaining_focus);
 
@@ -404,6 +418,9 @@ class OmniboxEditModel : public AutocompleteControllerDelegate {
   // Whether the edit has focus.
   bool has_focus_;
 
+  // Is the caret visible? Only meaningful if has_focus_ is true.
+  bool is_caret_visible_;
+
   // The URL of the currently displayed page.
   string16 permanent_text_;