Cleanup: Remove unused variables in chrome/ found by Scythe.

chrome/browser/ui/zoom/zoom_controller_browsertest.cc

 // Copyright 2014 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 "components/ui/zoom/zoom_controller.h"
 
 #include "base/prefs/pref_service.h"
 #include "base/process/kill.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 24 matching lines @@
          lhs.new_zoom_level == rhs.new_zoom_level &&
          lhs.zoom_mode == rhs.zoom_mode &&
          lhs.can_show_bubble == rhs.can_show_bubble;
 }
 
 class ZoomChangedWatcher : public ZoomObserver {
  public:
   ZoomChangedWatcher(
       content::WebContents* web_contents,
       const ZoomController::ZoomChangedEventData& expected_event_data)
-      : web_contents_(web_contents),
-        expected_event_data_(expected_event_data),
+      : expected_event_data_(expected_event_data),
         message_loop_runner_(new content::MessageLoopRunner) {
     ZoomController::FromWebContents(web_contents)->AddObserver(this);
   }
   ~ZoomChangedWatcher() override {}
 
   void Wait() { message_loop_runner_->Run(); }
 
   void OnZoomChanged(
       const ZoomController::ZoomChangedEventData& event_data) override {
     if (event_data == expected_event_data_)
       message_loop_runner_->Quit();
   }
 
  private:
-  content::WebContents* web_contents_;
   ZoomController::ZoomChangedEventData expected_event_data_;
   scoped_refptr<content::MessageLoopRunner> message_loop_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(ZoomChangedWatcher);
 };
 
 class ZoomControllerBrowserTest : public InProcessBrowserTest {
  public:
   ZoomControllerBrowserTest() {}
   ~ZoomControllerBrowserTest() override {}
@@ skipping 264 matching lines @@
       web_contents,
       old_zoom_level,
       new_zoom_level,
       ZoomController::ZOOM_MODE_DEFAULT,
       true);  // We have a non-empty host, so this will be 'true'.
   ZoomChangedWatcher zoom_change_watcher(web_contents, zoom_change_data);
   zoom_controller->SetZoomLevel(new_zoom_level);
   zoom_change_watcher.Wait();
 }
 #endif  // !defined(OS_CHROMEOS)