[iOS Clean] Created OverlayService.

ios/clean/chrome/browser/ui/overlays/browser_coordinator+overlay_support.mm

Index: ios/clean/chrome/browser/ui/overlays/browser_coordinator+overlay_support.mm
diff --git a/ios/clean/chrome/browser/ui/overlays/browser_coordinator+overlay_support.mm b/ios/clean/chrome/browser/ui/overlays/browser_coordinator+overlay_support.mm
new file mode 100644
index 0000000000000000000000000000000000000000..1348eff0f6bc4c18fab1183fa67c0ecac303edc5
--- /dev/null
+++ b/ios/clean/chrome/browser/ui/overlays/browser_coordinator+overlay_support.mm
@@ -0,0 +1,53 @@
+// 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/clean/chrome/browser/ui/overlays/browser_coordinator+overlay_support.h"
+
+#import <objc/runtime.h>
+
+#include "base/logging.h"
+#import "ios/clean/chrome/browser/ui/overlays/overlay_queue.h"
+#import "ios/shared/chrome/browser/ui/coordinators/browser_coordinator+internal.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+const void* const kOverlayQueuePropertyKey = &kOverlayQueuePropertyKey;
+}
+
+@implementation BrowserCoordinator (OverlaySupport)
+
+- (BOOL)supportsOverlaying {
+  return NO;
+}
+
+- (void)setQueue:(OverlayQueue*)queue {
+  NSValue* ptrValue = [NSValue valueWithPointer:queue];
+  objc_setAssociatedObject(self, kOverlayQueuePropertyKey, ptrValue,

[marq (ping after 24h), 2017/06/21 09:41:53]

I don't think encapsulation is worth the complexity of associated objects. If
coordinators need this as a property, they should have it.

You can define the property in the +overlay_support header along with @dynamic
instead of @synthesize, and then define the ivar in the main.mm along with
@synthesize.

[kkhorimoto, 2017/06/23 06:11:15]

Done.

+                           OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+}
+
+- (OverlayQueue*)queue {
+  NSValue* ptrValue = objc_getAssociatedObject(self, kOverlayQueuePropertyKey);
+  return static_cast<OverlayQueue*>([ptrValue pointerValue]);
+}
+
+- (void)startOverlayingCoordinator:(BrowserCoordinator*)overlayParent {
+  DCHECK(overlayParent);
+  [overlayParent addChildCoordinator:self];
+  [self start];
+}
+
+- (void)overlayWasStopped {
+  [self.parentCoordinator removeChildCoordinator:self];
+  self.queue->OverlayWasStopped(self);
+}
+
+- (void)cancelOverlay {
+  // Implemented by subclasses.
+}
+
+@end