Instant: Use only one hidden WebContents per profile.

chrome/browser/instant/instant_preview_controller.cc

Index: chrome/browser/instant/instant_preview_controller.cc
diff --git a/chrome/browser/instant/instant_preview_controller.cc b/chrome/browser/instant/instant_preview_controller.cc
deleted file mode 100644
index a728fc81abd1077753120cf25a3a17d12b9f10d0..0000000000000000000000000000000000000000
--- a/chrome/browser/instant/instant_preview_controller.cc
+++ /dev/null
@@ -1,19 +0,0 @@
-// 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/instant/instant_preview_controller.h"
-
-#include "chrome/browser/ui/browser.h"
-#include "chrome/browser/ui/browser_instant_controller.h"
-
-InstantPreviewController::InstantPreviewController(Browser* browser)
-    : browser_(browser) {
-  if (browser_->instant_controller())
-    browser_->instant_controller()->instant()->model()->AddObserver(this);
-}
-
-InstantPreviewController::~InstantPreviewController() {
-  if (browser_->instant_controller())
-    browser_->instant_controller()->instant()->model()->RemoveObserver(this);
-}