[multiball] Move mainCoordinator to SceneController.

Reparents the tab grid to SceneController. Note that the lazy getter
loses a DCHECK - it seems too hard to cleanly port to SceneController
at the moment, though once multiwindow is operational we should add new
invariant checks everywhere.

Bug: 1045657
Change-Id: I7e4eecd58bea4338a634f9e01e2cbc255c49c328
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2087337
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747694}

ios/chrome/app/main_controller.mm

@@ -125,7 +125,6 @@
 #import "ios/chrome/browser/ui/main/browser_view_wrangler.h"
 #import "ios/chrome/browser/ui/main/scene_controller_guts.h"
 #import "ios/chrome/browser/ui/settings/settings_navigation_controller.h"
-#include "ios/chrome/browser/ui/tab_grid/tab_grid_coordinator.h"
 #import "ios/chrome/browser/ui/ui_feature_flags.h"
 #include "ios/chrome/browser/ui/util/ui_util.h"
 #import "ios/chrome/browser/ui/util/uikit_ui_util.h"
@@ -319,11 +318,6 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
 // The ChromeBrowserState associated with the main (non-OTR) browsing mode.
 @property(nonatomic, assign) ChromeBrowserState* mainBrowserState;  // Weak.
 
-// The main coordinator, lazily created the first time it is accessed. Manages
-// the main view controller. This property should not be accessed before the
-// browser has started up to the FOREGROUND stage.
-@property(nonatomic, readonly) TabGridCoordinator* mainCoordinator;
-
 // Returns whether the restore infobar should be displayed.
 - (bool)mustShowRestoreInfobar;
 // Returns the set of the sessions ids of the tabs in the given |tabModel|.
@@ -402,8 +396,6 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
 @synthesize isColdStart = _isColdStart;
 @synthesize startupParameters = _startupParameters;
 @synthesize appLaunchTime = _appLaunchTime;
-// Defined in private interface
-@synthesize mainCoordinator = _mainCoordinator;
 @synthesize tabSwitcherIsActive;
 
 #pragma mark - Application lifecycle
@@ -665,24 +657,6 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
   return self.sceneController.browserViewWrangler;
 }
 
-- (TabGridCoordinator*)mainCoordinator {
-  if (_browserInitializationStage == INITIALIZATION_STAGE_BASIC) {
-    NOTREACHED() << "mainCoordinator accessed too early in initialization.";
-    return nil;
-  }
-  if (!_mainCoordinator) {
-    // Lazily create the main coordinator.
-    TabGridCoordinator* tabGridCoordinator =
-        [[TabGridCoordinator alloc] initWithWindow:self.window
-                        applicationCommandEndpoint:self.sceneController
-                       browsingDataCommandEndpoint:self];
-    tabGridCoordinator.regularBrowser = self.mainBrowser;
-    tabGridCoordinator.incognitoBrowser = self.otrBrowser;
-    _mainCoordinator = tabGridCoordinator;
-  }
-  return _mainCoordinator;
-}
-
 - (BOOL)isFirstLaunchAfterUpgrade {
   return [[PreviousSessionInfo sharedInstance] isFirstSessionAfterUpgrade];
 }
@@ -718,15 +692,6 @@ void MainControllerAuthenticationServiceDelegate::ClearBrowsingData(
 
   // Teardown UI state that is associated with scenes.
   [self.sceneController teardownUI];
-
-  [_mainCoordinator stop];
-  _mainCoordinator = nil;
-
-  // Invariant: The UI is stopped before the model is shutdown.
-  DCHECK(!_mainCoordinator);
-  [self.sceneController.browserViewWrangler shutdown];
-  self.sceneController.browserViewWrangler = nil;
-
   // End of per-window code.
 
   OmahaService::Stop();

ios/chrome/app/main_controller_guts.h

@@ -46,7 +46,6 @@ class ChromeBrowserState;
 - (BrowserViewController*)currentBVC;
 - (BrowserViewController*)mainBVC;
 - (BrowserViewController*)otrBVC;
-- (TabGridCoordinator*)mainCoordinator;
 - (id<BrowserInterfaceProvider>)interfaceProvider;
 - (UIWindow*)window;
 - (NSDictionary*)launchOptions;

ios/chrome/browser/ui/main/scene_controller.mm

@@ -165,6 +165,11 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
 // in a modal dialog.
 @property(nonatomic, assign) BOOL presentingFirstRunUI;
 
+// The main coordinator, lazily created the first time it is accessed. Manages
+// the main view controller. This property should not be accessed before the
+// browser has started up to the FOREGROUND stage.
+@property(nonatomic, strong) TabGridCoordinator* mainCoordinator;
+
 @end
 
 @implementation SceneController
@@ -196,6 +201,20 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
 
 #pragma mark - Setters and getters
 
+- (TabGridCoordinator*)mainCoordinator {
+  if (!_mainCoordinator) {
+    // Lazily create the main coordinator.
+    TabGridCoordinator* tabGridCoordinator =
+        [[TabGridCoordinator alloc] initWithWindow:self.sceneState.window
+                        applicationCommandEndpoint:self
+                       browsingDataCommandEndpoint:self.mainController];
+    tabGridCoordinator.regularBrowser = self.mainInterface.browser;
+    tabGridCoordinator.incognitoBrowser = self.incognitoInterface.browser;
+    _mainCoordinator = tabGridCoordinator;
+  }
+  return _mainCoordinator;
+}
+
 - (id<BrowserInterface>)mainInterface {
   return self.mainController.interfaceProvider.mainInterface;
 }
@@ -312,9 +331,9 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
   [self.mainController.window makeKeyAndVisible];
 
   // Lazy init of mainCoordinator.
-  [self.mainController.mainCoordinator start];
+  [self.mainCoordinator start];
 
-  _tabSwitcher = self.mainController.mainCoordinator.tabSwitcher;
+  _tabSwitcher = self.mainCoordinator.tabSwitcher;
   // Call -restoreInternalState so that the grid shows the correct panel.
   [_tabSwitcher
       restoreInternalStateWithMainBrowser:self.mainInterface.browser
@@ -372,6 +391,12 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
   [self.historyCoordinator stop];
   self.historyCoordinator = nil;
 
+  [_mainCoordinator stop];
+  _mainCoordinator = nil;
+
+  [self.browserViewWrangler shutdown];
+  self.browserViewWrangler = nil;
+
   self.hasInitializedUI = NO;
 }
 
@@ -525,8 +550,7 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
                                     snapshotResult);
         });
   }
-  [self.mainController.mainCoordinator
-      prepareToShowTabSwitcher:self.tabSwitcher];
+  [self.mainCoordinator prepareToShowTabSwitcher:self.tabSwitcher];
 }
 
 - (void)displayTabSwitcher {
@@ -689,7 +713,7 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
   DCHECK(!self.signinInteractionCoordinator.isSettingsViewPresented);
   if (!baseViewController) {
     DCHECK_EQ(self.mainController.currentBVC,
-              self.mainController.mainCoordinator.activeViewController);
+              self.mainCoordinator.activeViewController);
     baseViewController = self.mainController.currentBVC;
   }
 
@@ -718,7 +742,7 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
   DCHECK(!self.signinInteractionCoordinator.isSettingsViewPresented);
   if (!baseViewController) {
     DCHECK_EQ(self.mainController.currentBVC,
-              self.mainController.mainCoordinator.activeViewController);
+              self.mainCoordinator.activeViewController);
     baseViewController = self.mainController.currentBVC;
   }
 
@@ -852,8 +876,7 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
 }
 
 - (UIImage*)currentPageScreenshot {
-  UIView* lastView =
-      self.mainController.mainCoordinator.activeViewController.view;
+  UIView* lastView = self.mainCoordinator.activeViewController.view;
   DCHECK(lastView);
   CGFloat scale = 0.0;
   // For screenshots of the tab switcher we need to use a scale of 1.0 to avoid
@@ -945,7 +968,7 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
   // The tab switcher dismissal animation runs
   // as part of the BVC presentation process.  The BVC is presented before the
   // animations begin, so it should be the current active VC at this point.
-  DCHECK_EQ(self.mainController.mainCoordinator.activeViewController,
+  DCHECK_EQ(self.mainCoordinator.activeViewController,
             self.mainController.currentBVC);
 
   if (self.modeToDisplayOnTabSwitcherDismissal ==
@@ -1161,9 +1184,8 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
     [self.signinInteractionCoordinator cancelAndDismiss];
     // History coordinator can be started on top of the tab grid. This is not
     // true of the other tab switchers.
-    DCHECK(self.mainController.mainCoordinator);
-    [self.mainController.mainCoordinator
-        stopChildCoordinatorsWithCompletion:completion];
+    DCHECK(self.mainCoordinator);
+    [self.mainCoordinator stopChildCoordinatorsWithCompletion:completion];
   };
 
   // As a top level rule, if the settings are showing, they need to be
@@ -1400,9 +1422,8 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
       [weakCurrentBVC.dispatcher focusOmnibox];
     };
   }
-  [self.mainController.mainCoordinator
-      showTabViewController:self.currentInterface.bvc
-                 completion:completion];
+  [self.mainCoordinator showTabViewController:self.currentInterface.bvc
+                                   completion:completion];
   [self.currentInterface.bvc.dispatcher
       setIncognitoContentVisible:(self.currentInterface ==
                                   self.incognitoInterface)];
@@ -1456,7 +1477,7 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
   // TODO(crbug.com/754642): Implement TopPresentedViewControllerFrom()
   // privately.
   return top_view_controller::TopPresentedViewControllerFrom(
-      self.mainController.mainCoordinator.viewController);
+      self.mainCoordinator.viewController);
 }
 
 #pragma mark - WebStateListObserving
@@ -1570,7 +1591,7 @@ const NSTimeInterval kDisplayPromoDelay = 0.1;
   self.mainController.tabSwitcherIsActive = YES;
   [self.tabSwitcher setDelegate:self];
 
-  [self.mainController.mainCoordinator showTabSwitcher:self.tabSwitcher];
+  [self.mainCoordinator showTabSwitcher:self.tabSwitcher];
 }
 
 // Destroys and rebuilds the incognito browser state.