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

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=pkl@chromium.org

Bug: 1042208
Change-Id: Ie8a877a9f2a073e891ce7da50d6d517756a7c5da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2010766
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Peter Lee <pkl@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733553}

ios/chrome/browser/ui/activity_services/activity_service_legacy_coordinator.h

@@ -5,6 +5,7 @@
 #ifndef IOS_CHROME_BROWSER_UI_ACTIVITY_SERVICES_ACTIVITY_SERVICE_LEGACY_COORDINATOR_H_
 #define IOS_CHROME_BROWSER_UI_ACTIVITY_SERVICES_ACTIVITY_SERVICE_LEGACY_COORDINATOR_H_
 
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 #import "ios/chrome/browser/ui/coordinators/chrome_coordinator.h"
 
 @protocol ActivityServicePositioner;
@@ -12,10 +13,6 @@
 @class CommandDispatcher;
 @class TabModel;
 
-namespace ios {
-class ChromeBrowserState;
-}  // namespace
-
 // ActivityServiceLegacyCoordinator provides a public interface for the share
 // menu feature.
 @interface ActivityServiceLegacyCoordinator : ChromeCoordinator

ios/chrome/browser/ui/activity_services/share_protocol.h

@@ -8,6 +8,8 @@
 #import <Foundation/Foundation.h>
 #import <UIKit/UIKit.h>
 
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
+
 @protocol ActivityServicePassword;
 @protocol ActivityServicePositioner;
 @protocol ActivityServicePresentation;
@@ -15,10 +17,6 @@
 @class ShareToData;
 @protocol SnackbarCommands;
 
-namespace ios {
-class ChromeBrowserState;
-}
-
 namespace ShareTo {
 
 // Provides the result of a sharing event.