[iOS Clean] Removed old overlay implementation.

ios/shared/chrome/browser/ui/coordinators/browser_coordinator_unittest.mm

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/shared/chrome/browser/ui/coordinators/browser_coordinator+internal.h"
 #import "ios/shared/chrome/browser/ui/coordinators/browser_coordinator.h"
 
 #import "ios/shared/chrome/browser/ui/coordinators/browser_coordinator_test.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ skipping 103 matching lines @@
   TestCoordinator* otherParent = [[TestCoordinator alloc] init];
   TestCoordinator* otherChild = [[TestCoordinator alloc] init];
   [otherParent addChildCoordinator:otherChild];
 
   // -removeChildCoordinator of a non-child should have no affect.
   [parent removeChildCoordinator:otherChild];
   EXPECT_TRUE([otherParent.children containsObject:otherChild]);
   EXPECT_EQ(otherParent, otherChild.parentCoordinator);
 }
 
-TEST_F(BrowserCoordinatorTest, TestOverlay) {
-  TestCoordinator* parent = [[TestCoordinator alloc] init];
-  TestCoordinator* child = [[TestCoordinator alloc] init];
-  TestCoordinator* grandchild = [[TestCoordinator alloc] init];
-  TestCoordinator* overlay = [[TestCoordinator alloc] init];
-  TestCoordinator* secondOverlay = [[TestCoordinator alloc] init];
-
-  EXPECT_TRUE([parent canAddOverlayCoordinator:overlay]);
-  [parent addChildCoordinator:child];
-  [child addChildCoordinator:grandchild];
-  EXPECT_FALSE([parent canAddOverlayCoordinator:overlay]);
-  EXPECT_FALSE([child canAddOverlayCoordinator:overlay]);
-  EXPECT_TRUE([grandchild canAddOverlayCoordinator:overlay]);
-  EXPECT_FALSE([grandchild canAddOverlayCoordinator:child]);
-
-  EXPECT_FALSE(overlay.overlaying);
-  [parent addOverlayCoordinator:overlay];
-  EXPECT_TRUE(overlay.overlaying);
-  EXPECT_EQ(overlay, parent.overlayCoordinator);
-  EXPECT_EQ(overlay, child.overlayCoordinator);
-  EXPECT_EQ(overlay, grandchild.overlayCoordinator);
-  EXPECT_TRUE([grandchild.children containsObject:overlay]);
-  EXPECT_EQ(grandchild, overlay.parentCoordinator);
-
-  // Shouldn't be able to add a second overlaying coordinator.
-  EXPECT_FALSE([grandchild canAddOverlayCoordinator:secondOverlay]);
-  EXPECT_FALSE(secondOverlay.overlaying);
-  [parent addOverlayCoordinator:secondOverlay];
-  EXPECT_FALSE(secondOverlay.overlaying);
-
-  [child removeOverlayCoordinator];
-  EXPECT_FALSE(overlay.overlaying);
-  EXPECT_EQ(nil, parent.overlayCoordinator);
-  EXPECT_EQ(nil, child.overlayCoordinator);
-  EXPECT_EQ(nil, grandchild.overlayCoordinator);
-  EXPECT_FALSE([grandchild.children containsObject:overlay]);
-  EXPECT_EQ(nil, overlay.parentCoordinator);
-
-  // An implementation that doesn't allow any overlays shouldn't get one.
-  NonOverlayableCoordinator* noOverlays =
-      [[NonOverlayableCoordinator alloc] init];
-  TestCoordinator* thirdOverlay = [[TestCoordinator alloc] init];
-
-  EXPECT_FALSE([noOverlays canAddOverlayCoordinator:thirdOverlay]);
-  EXPECT_FALSE(thirdOverlay.overlaying);
-  [noOverlays addOverlayCoordinator:thirdOverlay];
-  EXPECT_FALSE(thirdOverlay.overlaying);
-}
-
 TEST_F(BrowserCoordinatorTest, AddedRemoved) {
   TestCoordinator* parent = [[TestCoordinator alloc] init];
   TestCoordinator* child = [[TestCoordinator alloc] init];
 
   // Add to the parent.
   EXPECT_FALSE(child.wasAddedCalled);
   EXPECT_FALSE(child.willBeRemovedCalled);
   [parent addChildCoordinator:child];
   EXPECT_TRUE(child.wasAddedCalled);
   EXPECT_FALSE(child.willBeRemovedCalled);
@@ skipping 113 matching lines @@
   TestCoordinator* child = [[TestCoordinator alloc] init];
   TestCoordinator* grandChild1 = [[TestCoordinator alloc] init];
   TestCoordinator* grandChild2 = [[TestCoordinator alloc] init];
   [child addChildCoordinator:grandChild1];
   [child addChildCoordinator:grandChild2];
   [parent addChildCoordinator:child];
 
   // Remove the child.
   [parent removeChildCoordinator:child];
 }