[multiball] Cleanup Scene/Main Controller Guts.

Cleans up the Guts protocols from things that are no longer used.
Uses interfaceProvider everywhere instead of alternative accessors.

Bug: 1045659, 1045660
Change-Id: Ib3355505686c6b034e98373d380330dff256d8af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2087675
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748190}

ios/chrome/app/main_controller.mm

@@ -1164,7 +1164,10 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
 }
 
 - (ChromeBrowserState*)currentBrowserState {
-  return self.currentBVC.browserState;
+  if (!self.interfaceProvider.currentInterface.browser) {
+    return nullptr;
+  }
+  return self.interfaceProvider.currentInterface.browser->GetBrowserState();
 }
 
 - (bool)mustShowRestoreInfobar {
@@ -1206,12 +1209,6 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
 
 
 
-#pragma mark - SceneController plumbing
-
-- (BOOL)currentPageIsIncognito {
-  return [self currentBrowserState] -> IsOffTheRecord();
-}
-
 #pragma mark - BrowsingDataCommands
 
 - (void)removeBrowsingDataForBrowserState:(ChromeBrowserState*)browserState

ios/chrome/app/main_controller_guts.h

@@ -16,10 +16,7 @@
 #import "ios/chrome/browser/ui/commands/browsing_data_commands.h"
 
 @class AppState;
-@class BrowserViewController;
 class ChromeBrowserState;
-@class TabGridCoordinator;
-@protocol BrowserInterfaceProvider;
 
 // TODO(crbug.com/1012697): Remove this protocol when SceneController is
 // operational. Move the private internals back into MainController, and pass
@@ -40,13 +37,7 @@ class ChromeBrowserState;
 // Keeps track of the restore state during startup.
 @property(nonatomic, strong) CrashRestoreHelper* restoreHelper;
 
-- (TabModel*)currentTabModel;
 - (ChromeBrowserState*)mainBrowserState;
-- (ChromeBrowserState*)currentBrowserState;
-- (BrowserViewController*)currentBVC;
-- (BrowserViewController*)mainBVC;
-- (BrowserViewController*)otrBVC;
-- (id<BrowserInterfaceProvider>)interfaceProvider;
 - (UIWindow*)window;
 - (NSDictionary*)launchOptions;
 - (AppState*)appState;

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

@@ -17,7 +17,6 @@
 
 class ChromeBrowserState;
 @class BrowserViewWrangler;
-@class TabModel;
 
 @protocol SceneControllerGuts <WebStateListObserving>
 
@@ -26,24 +25,9 @@ class ChromeBrowserState;
 // BrowserViewInformation protocol.
 @property(nonatomic, strong) BrowserViewWrangler* browserViewWrangler;
 
-// The scene level component for url loading. Is passed down to
-// browser state level UrlLoadingService instances.
-@property(nonatomic, assign) AppUrlLoadingService* appURLLoadingService;
-
 - (void)startUpChromeUIPostCrash:(BOOL)isPostCrashLaunch
                  needRestoration:(BOOL)needsRestoration;
 
-- (void)dismissModalDialogsWithCompletion:(ProceduralBlock)completion
-                           dismissOmnibox:(BOOL)dismissOmnibox;
-
-- (void)openSelectedTabInMode:(ApplicationModeForTabOpening)tabOpeningTargetMode
-            withUrlLoadParams:(const UrlLoadParams&)urlLoadParams
-                   completion:(ProceduralBlock)completion;
-
-- (void)openTabFromLaunchOptions:(NSDictionary*)launchOptions
-              startupInformation:(id<StartupInformation>)startupInformation
-                        appState:(AppState*)appState;
-
 - (void)dismissModalsAndOpenSelectedTabInMode:
             (ApplicationModeForTabOpening)targetMode
                             withUrlLoadParams:
@@ -51,27 +35,15 @@ class ChromeBrowserState;
                                dismissOmnibox:(BOOL)dismissOmnibox
                                    completion:(ProceduralBlock)completion;
 
-- (BOOL)shouldOpenNTPTabOnActivationOfTabModel:(TabModel*)tabModel;
-
-// TabSwitcherDelegate helpers
-
-// Begins the process of dismissing the tab switcher with the given current
-// model, switching which BVC is suspended if necessary, but not updating the
-// UI.  The omnibox will be focused after the tab switcher dismissal is
-// completed if |focusOmnibox| is YES.
-- (void)beginDismissingTabSwitcherWithCurrentModel:(TabModel*)tabModel
-                                      focusOmnibox:(BOOL)focusOmnibox;
-// Completes the process of dismissing the tab switcher, removing it from the
-// screen and showing the appropriate BVC.
-- (void)finishDismissingTabSwitcher;
-
-- (BOOL)presentingFirstRunUI;
-
 // Testing only.
+- (BOOL)presentingFirstRunUI;
 - (void)showFirstRunUI;
 - (void)setTabSwitcher:(id<TabSwitcher>)switcher;
 - (id<TabSwitcher>)tabSwitcher;
 
+- (void)dismissModalDialogsWithCompletion:(ProceduralBlock)completion
+                           dismissOmnibox:(BOOL)dismissOmnibox;
+
 #pragma mark - AppNavigation helpers
 
 // Presents a SignedInAccountsViewController for |browserState| on the top view
@@ -79,12 +51,6 @@ class ChromeBrowserState;
 - (void)presentSignedInAccountsViewControllerForBrowserState:
     (ChromeBrowserState*)browserState;
 
-// Clears incognito data that is specific to iOS and won't be cleared by
-// deleting the browser state.
-- (void)clearIOSSpecificIncognitoData;
-
-- (void)activateBVCAndMakeCurrentBVCPrimary;
-
 #pragma mark - iOS 12 compat
 
 // Method called on SceneController when the scene disconnects. Exposed here for