Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/ui/omnibox/omnibox_edit_model.cc

Index: chrome/browser/ui/omnibox/omnibox_edit_model.cc
diff --git a/chrome/browser/ui/omnibox/omnibox_edit_model.cc b/chrome/browser/ui/omnibox/omnibox_edit_model.cc
index a643b741f48e4bc489b1209229f0d42b350a248c..66865b99bbb88f165df72b6266fb96639efab1a4 100644
--- a/chrome/browser/ui/omnibox/omnibox_edit_model.cc
+++ b/chrome/browser/ui/omnibox/omnibox_edit_model.cc
@@ -725,6 +725,11 @@ void OmniboxEditModel::OnSetFocus(bool control_down) {
   NotifySearchTabHelper();
 }
 
+void OmniboxEditModel::OnFocusVisibilityChange(bool visible_focus) {
+  focus_is_visible_ = visible_focus;
+  // TODO(samarth): communicate this state to InstantController.
+}
+
 void OmniboxEditModel::OnWillKillFocus(gfx::NativeView view_gaining_focus) {
   SetInstantSuggestion(InstantSuggestion());
 
@@ -738,6 +743,7 @@ void OmniboxEditModel::OnWillKillFocus(gfx::NativeView view_gaining_focus) {
 
 void OmniboxEditModel::OnKillFocus() {
   has_focus_ = false;
+  focus_is_visible_ = false;
   control_key_state_ = UP;
   paste_state_ = NONE;
 }