[iOS Clean] Created OverlayService.

ios/clean/chrome/browser/ui/overlays/overlay_service_impl.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/clean/chrome/browser/ui/overlays/overlay_service_impl.h"
+
+#include "base/logging.h"
+#import "ios/chrome/browser/web_state_list/web_state_list.h"
+#import "ios/clean/chrome/browser/ui/overlays/browser_coordinator+overlay_support.h"
+#import "ios/clean/chrome/browser/ui/overlays/browser_overlay_queue.h"
+#import "ios/clean/chrome/browser/ui/overlays/overlay_scheduler.h"
+#import "ios/clean/chrome/browser/ui/overlays/web_state_overlay_queue.h"
+#import "ios/shared/chrome/browser/ui/browser_list/browser_list.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+OverlayServiceImpl::OverlayServiceImpl(BrowserList* browser_list)
+    : browser_list_(browser_list) {
+  DCHECK(browser_list_);
+  for (int i = 0; i < browser_list_->count(); ++i)
+    StartSchedulerForBrowser(browser_list_->GetBrowserAtIndex(i));
+  browser_list_->AddObserver(this);
+}
+
+void OverlayServiceImpl::OnBrowserCreated(BrowserList* browser_list,
+                                          Browser* browser) {
+  DCHECK_EQ(browser_list, browser_list_);
+  StartSchedulerForBrowser(browser);
+}
+
+void OverlayServiceImpl::OnBrowserRemoved(BrowserList* browser_list,
+                                          Browser* browser) {
+  DCHECK_EQ(browser_list, browser_list_);
+  StopSchedulerForBrowser(browser);
+}
+
+void OverlayServiceImpl::Shutdown() {
+  for (int i = 0; i < browser_list_->count(); ++i)
+    StopSchedulerForBrowser(browser_list_->GetBrowserAtIndex(i));
+  browser_list_->RemoveObserver(this);
+}
+
+bool OverlayServiceImpl::IsBrowserShowingOverlay(Browser* browser) const {
+  if (browser_list_->GetIndexOfBrowser(browser) == BrowserList::kInvalidIndex)
+    return false;
+  OverlayScheduler* scheduler = OverlayScheduler::FromBrowser(browser);
+  return scheduler && scheduler->IsShowingOverlay();
+}
+
+void OverlayServiceImpl::ReplaceVisibleOverlay(
+    BrowserCoordinator* overlay_coordinator,
+    Browser* browser) {
+  DCHECK(overlay_coordinator);
+  DCHECK(IsBrowserShowingOverlay(browser));
+  OverlayScheduler::FromBrowser(browser)->ReplaceVisibleOverlay(
+      overlay_coordinator);
+}
+
+void OverlayServiceImpl::ShowOverlayForWebState(
+    BrowserCoordinator* overlay_coordinator,
+    web::WebState* web_state) {
+  DCHECK(overlay_coordinator.supportsOverlaying);
+  WebStateOverlayQueue::FromWebState(web_state)->AddWebStateOverlay(
+      overlay_coordinator);
+}
+
+void OverlayServiceImpl::SetWebStateParentCoordinator(
+    BrowserCoordinator* parent_coordinator,
+    web::WebState* web_state) {
+  WebStateOverlayQueue::FromWebState(web_state)->SetWebStateParentCoordinator(
+      parent_coordinator);
+}
+
+void OverlayServiceImpl::ShowOverlayForBrowser(
+    BrowserCoordinator* overlay_coordinator,
+    BrowserCoordinator* parent_coordiantor,
+    Browser* browser) {
+  DCHECK(overlay_coordinator.supportsOverlaying);
+  BrowserOverlayQueue::FromBrowser(browser)->AddBrowserOverlay(
+      overlay_coordinator, parent_coordiantor);
+}
+
+void OverlayServiceImpl::CancelOverlays() {
+  for (int i = 0; i < browser_list_->count(); ++i) {
+    OverlayScheduler::FromBrowser(browser_list_->GetBrowserAtIndex(i))
+        ->CancelOverlays();
+  }
+}
+
+void OverlayServiceImpl::CancelOverlayForWebState(web::WebState* web_state) {
+  WebStateOverlayQueue::FromWebState(web_state)->CancelOverlays();
+}
+
+void OverlayServiceImpl::StartSchedulerForBrowser(Browser* browser) {
+  OverlayScheduler::CreateForBrowser(browser);
+}
+
+void OverlayServiceImpl::StopSchedulerForBrowser(Browser* browser) {
+  OverlayScheduler::FromBrowser(browser)->StopObservingBrowser();
+}