[ios] Moves find-in-page code out of Tab and into FindTabHelper.

ios/chrome/browser/tabs/tab.h

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_TABS_TAB_H_
 #define IOS_CHROME_BROWSER_TABS_TAB_H_
 
 #import <UIKit/UIKit.h>
 
 #include <memory>
 #include <vector>
 
 #import "components/signin/ios/browser/manage_accounts_delegate.h"
 #include "ios/net/request_tracker.h"
 #import "ios/web/public/web_state/ui/crw_web_delegate.h"
 #include "ui/base/page_transition_types.h"
 
 @class AutofillController;
 @class AutoReloadBridge;
 @class CastController;
 @protocol CRWNativeContentProvider;
 @class CRWSessionEntry;
 @class CRWWebController;
 @class ExternalAppLauncher;
-@class FindInPageController;
 @class FormInputAccessoryViewController;
 @class FullScreenController;
 @protocol FullScreenControllerDelegate;
 class GURL;
 @class NativeAppNavigationController;
 @class OpenInController;
 @class OverscrollActionsController;
 @protocol OverscrollActionsControllerDelegate;
 @protocol PassKitDialogProvider;
 @class PasswordController;
@@ skipping 236 matching lines @@
 - (void)switchToReaderMode;
 
 // Update internal state to use the desktop user agent. Must call
 // -reloadWebViewAndURL for changes to take effect.
 - (void)enableDesktopUserAgent;
 
 // Remove the UIWebView and reload the current url.  Used by request desktop
 // so the updated user agent is used.
 - (void)reloadForDesktopUserAgent;
 
-// Accessor for Find in Page Controller.
-- (FindInPageController*)findInPageController;
-
 // Ensures the toolbar visibility matches |visible|.
 - (void)updateFullscreenWithToolbarVisible:(BOOL)visible;
 
 // Returns a snapshot of the current page, backed by disk so it can be purged
 // and reloaded easily. The snapshot may be in memory, saved on disk or not
 // present at all.
 // 1) If the snapshot is in memory |block| will be called synchronously with
 // the existing image.
 // 2) If the snapshot is saven on disk |block| will be called asynchronously
 // once the image is retrieved.
@@ skipping 39 matching lines @@
 
 // Called when this tab is hidden.
 - (void)wasHidden;
 
 // Evaluates U2F result.
 - (void)evaluateU2FResultFromURL:(const GURL&)url;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_TABS_TAB_H_