Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/instant/instant_controller.h

Index: chrome/browser/instant/instant_controller.h
diff --git a/chrome/browser/instant/instant_controller.h b/chrome/browser/instant/instant_controller.h
index 436f9866560268177df9731e72a553709fb0e405..f3448cd557667c6f429a69a8d7c9578ee9a5356c 100644
--- a/chrome/browser/instant/instant_controller.h
+++ b/chrome/browser/instant/instant_controller.h
@@ -127,6 +127,10 @@ class InstantController {
                           int height,
                           InstantSizeUnits units);
 
+  // Invoked by InstantLoader to request the browser to start capturing user key
+  // strokes.
+  void StartCapturingKeyStrokes(InstantLoader* loader);
+
   // Invoked by InstantLoader when it has determined whether or not the page
   // supports the Instant API.
   void InstantSupportDetermined(InstantLoader* loader, bool supports_instant);