Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/instant/instant_tab.cc

Index: chrome/browser/instant/instant_tab.cc
diff --git a/chrome/browser/instant/instant_tab.cc b/chrome/browser/instant/instant_tab.cc
index c68217281feb098ed58373c12c1e8675450eeaa9..23085632d566e43e9a71465f0b23364935591c69 100644
--- a/chrome/browser/instant/instant_tab.cc
+++ b/chrome/browser/instant/instant_tab.cc
@@ -67,3 +67,11 @@ void InstantTab::ShowInstantPreview(InstantShownReason /* reason */,
                                     InstantSizeUnits /* units */) {
   // The page is a committed tab (i.e., always showing), so nothing to do.
 }
+
+void InstantTab::StartCapturingKeyStrokes() {
+  // We don't honor this call from committed tabs.
+}
+
+void InstantTab::StopCapturingKeyStrokes() {
+  // We don't honor this call from committed tabs.
+}