Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/instant/instant_controller.cc

Index: chrome/browser/instant/instant_controller.cc
diff --git a/chrome/browser/instant/instant_controller.cc b/chrome/browser/instant/instant_controller.cc
index 09aee030bad29ff4805634404b125bbe49b62af4..6810eac9946b564bab4ef057aa822a6c7ec77d65 100644
--- a/chrome/browser/instant/instant_controller.cc
+++ b/chrome/browser/instant/instant_controller.cc
@@ -618,6 +618,13 @@ void InstantController::InstantSupportDetermined(InstantLoader* loader,
       content::NotificationService::NoDetails());
 }
 
+void InstantController::OnWebSearchBoxFocusChange(InstantLoader* loader,
+                                                  bool is_focused) {
+  if (loader_ == loader && extended_enabled_ &&
+      model_.mode().is_ntp() && is_focused)
+    browser_->SetInvisibleFocus();
+}
+
 void InstantController::SwappedTabContents(InstantLoader* loader) {
   if (loader_ == loader)
     model_.SetPreviewContents(GetPreviewContents());