[ios] Use chrome_browser_state_forward.h in /ios/chrome/browser/ui/recent_tabs

Instead of forward declaring ChromeBrowserState in the ios
namespace, use a header. This will allow moving the class
to the global namespace without having to change all the
forward declaration at the same time.

This CL was uploaded by git cl split.

R=sczs@chromium.org

Bug: 1042208
Change-Id: I048c314ac3bdd58c9f871357f677de36c0b772e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2010781
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734029}

ios/chrome/browser/ui/recent_tabs/recent_tabs_mediator.h

@@ -7,14 +7,12 @@
 
 #import <Foundation/Foundation.h>
 
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 #import "ios/chrome/browser/ui/recent_tabs/closed_tabs_observer_bridge.h"
 #import "ios/chrome/browser/ui/recent_tabs/recent_tabs_table_view_controller_delegate.h"
 #import "ios/chrome/browser/ui/recent_tabs/synced_sessions_bridge.h"
 #import "ios/chrome/browser/ui/table_view/table_view_favicon_data_source.h"
 
-namespace ios {
-class ChromeBrowserState;
-}
 class WebStateList;
 
 @protocol RecentTabsConsumer;

ios/chrome/browser/ui/recent_tabs/recent_tabs_table_view_controller.h

@@ -5,13 +5,11 @@
 #ifndef IOS_CHROME_BROWSER_UI_RECENT_TABS_RECENT_TABS_TABLE_VIEW_CONTROLLER_H_
 #define IOS_CHROME_BROWSER_UI_RECENT_TABS_RECENT_TABS_TABLE_VIEW_CONTROLLER_H_
 
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 #import "ios/chrome/browser/ui/recent_tabs/recent_tabs_consumer.h"
 #import "ios/chrome/browser/ui/table_view/chrome_table_view_controller.h"
 #include "ui/base/window_open_disposition.h"
 
-namespace ios {
-class ChromeBrowserState;
-}
 enum class UrlLoadStrategy;
 class WebStateList;
 

ios/chrome/browser/ui/recent_tabs/synced_sessions_bridge.h

@@ -12,10 +12,7 @@
 #include "base/callback_list.h"
 #include "base/macros.h"
 #include "components/signin/public/identity_manager/identity_manager.h"
-
-namespace ios {
-class ChromeBrowserState;
-}
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 
 namespace signin {
 class IdentityManager;