Remove unused instant_overlay_controller_mac.h/mm

chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.mm

-// Copyright 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/browser/ui/cocoa/tab_contents/instant_overlay_controller_mac.h"
-
-#import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
-#include "chrome/browser/ui/search/instant_overlay_model.h"
-
-InstantOverlayControllerMac::InstantOverlayControllerMac(
-    Browser* browser,
-    OverlayableContentsController* overlay)
-    : InstantOverlayController(browser),
-      overlay_(overlay) {
-}
-
-InstantOverlayControllerMac::~InstantOverlayControllerMac() {
-}
-
-void InstantOverlayControllerMac::OverlayStateChanged(
-    const InstantOverlayModel& model) {
-  if (model.mode().is_ntp() || model.mode().is_search_suggestions()) {
-    // Drop shadow is only needed if search mode is not |NTP| and overlay does
-    // not fill up the entire contents page.
-    BOOL drawDropShadow = !model.mode().is_ntp() &&
-        !(model.height() == 100 &&
-          model.height_units() == INSTANT_SIZE_PERCENT);
-    [overlay_ setOverlay:model.GetOverlayContents()
-                  height:model.height()
-             heightUnits:model.height_units()
-          drawDropShadow:drawDropShadow];
-  } else if ([overlay_ isShowingOverlay]) {
-    [overlay_ setOverlay:NULL
-                  height:0
-             heightUnits:INSTANT_SIZE_PIXELS
-          drawDropShadow:NO];
-  }
-}