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

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=edchin@chromium.org

Bug: 1042208
Change-Id: I1dde40ae065191ba440a39173db12e06c4220fdf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2010787
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#733972}

ios/chrome/browser/ui/main/BUILD.gn

@@ -9,6 +9,7 @@ source_set("scene_guts") {
   deps = [
     "//ios/chrome/app/application_delegate:application_delegate_internal",
     "//ios/chrome/browser:utils",
+    "//ios/chrome/browser/browser_state:forward",
     "//ios/chrome/browser/url_loading",
     "//ios/chrome/browser/web_state_list",
   ]

ios/chrome/browser/ui/main/browser_interface_provider.h

@@ -8,16 +8,13 @@
 #import <UIKit/UIKit.h>
 
 #include "base/ios/block_types.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 
 class Browser;
 @class BrowserCoordinator;
 @class BrowserViewController;
 @class TabModel;
 
-namespace ios {
-class ChromeBrowserState;
-}
-
 // A BrowserInterface is an abstraction that exposes an interface to the Chrome
 // user interface (and related model objects) to the application layer. Each
 // BrowserInterface is roughly equivalent to a window on a desktop browser --

ios/chrome/browser/ui/main/browser_view_wrangler.h

@@ -7,6 +7,7 @@
 
 #import <UIKit/UIKit.h>
 
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 #import "ios/chrome/browser/ui/main/browser_interface_provider.h"
 
 @protocol ApplicationCommands;
@@ -17,10 +18,6 @@
 
 class AppUrlLoadingService;
 
-namespace ios {
-class ChromeBrowserState;
-}
-
 // Protocol for objects that can handle switching browser state storage.
 @protocol BrowserStateStorageSwitching
 - (void)changeStorageFromBrowserState:(ios::ChromeBrowserState*)oldState

ios/chrome/browser/ui/main/scene_controller_guts.h

@@ -9,16 +9,13 @@
 
 #include "ios/chrome/app/application_delegate/startup_information.h"
 #import "ios/chrome/app/application_delegate/tab_opening.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 #import "ios/chrome/browser/procedural_block_types.h"
 #import "ios/chrome/browser/url_loading/url_loading_params.h"
 #import "ios/chrome/browser/web_state_list/web_state_list_observer_bridge.h"
 
 @class TabModel;
 
-namespace ios {
-class ChromeBrowserState;
-}  // namespace ios
-
 @protocol SceneControllerGuts <WebStateListObserving>
 
 - (void)dismissModalDialogsWithCompletion:(ProceduralBlock)completion

ios/chrome/browser/ui/main/test/BUILD.gn

@@ -10,5 +10,8 @@ source_set("test") {
     "stub_browser_interface_provider.h",
     "stub_browser_interface_provider.mm",
   ]
-  deps = [ "//ios/chrome/browser/ui/main" ]
+  deps = [
+    "//ios/chrome/browser/browser_state:forward",
+    "//ios/chrome/browser/ui/main",
+  ]
 }

ios/chrome/browser/ui/main/test/stub_browser_interface.h

@@ -7,13 +7,11 @@
 
 #import <Foundation/Foundation.h>
 
+#include "ios/chrome/browser/browser_state/chrome_browser_state_forward.h"
 #import "ios/chrome/browser/ui/main/browser_interface_provider.h"
 
 class Browser;
 @class BrowserViewController;
-namespace ios {
-class ChromeBrowserState;
-}
 @class TabModel;
 
 // Test double for BrowserInterface implementors. All properties are writable,