[Reland] Enable AutoResize for Constrained Web Dialogs for Mac.

chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.mm

Index: chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.mm
diff --git a/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.mm b/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.mm
index 16f755c1971d44e92bfc34f6131b0128f3a3b67f..510402e87e5f70efec6eef06cc40d403eab1f815 100644
--- a/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.mm
+++ b/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.mm
@@ -11,35 +11,59 @@
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet.h"
 #import "chrome/browser/ui/cocoa/single_web_contents_dialog_manager_cocoa.h"
 #include "components/guest_view/browser/guest_view_base.h"
-#include "components/web_modal/web_contents_modal_dialog_manager.h"
 #include "content/public/browser/browser_thread.h"
 
 using web_modal::WebContentsModalDialogManager;
 
+std::unique_ptr<ConstrainedWindowMac> CreateAndShowWebModalDialogMac(
+    ConstrainedWindowMacDelegate* delegate,
+    content::WebContents* web_contents,
+    id<ConstrainedWindowSheet> sheet) {
+  ConstrainedWindowMac* window =
+      new ConstrainedWindowMac(delegate, web_contents, sheet);
+  window->ShowWebContentsModalDialog();
+  return std::unique_ptr<ConstrainedWindowMac>(window);
+}
+
+std::unique_ptr<ConstrainedWindowMac> CreateWebModalDialogMac(
+    ConstrainedWindowMacDelegate* delegate,
+    content::WebContents* web_contents,
+    id<ConstrainedWindowSheet> sheet) {
+  return std::unique_ptr<ConstrainedWindowMac>(
+      new ConstrainedWindowMac(delegate, web_contents, sheet));
+}
+
 ConstrainedWindowMac::ConstrainedWindowMac(
     ConstrainedWindowMacDelegate* delegate,
     content::WebContents* web_contents,
     id<ConstrainedWindowSheet> sheet)
-    : delegate_(delegate) {
+    : delegate_(delegate),
+      sheet_([sheet retain]) {
   DCHECK(sheet);
 
   // |web_contents| may be embedded within a chain of nested GuestViews. If it
   // is, follow the chain of embedders to the outermost WebContents and use it.
-  web_contents =
+  web_contents_ =
       guest_view::GuestViewBase::GetTopLevelWebContents(web_contents);
 
-  auto manager = WebContentsModalDialogManager::FromWebContents(web_contents);
-  scoped_ptr<SingleWebContentsDialogManagerCocoa> native_manager(
-      new SingleWebContentsDialogManagerCocoa(this, sheet, manager));
-  manager->ShowDialogWithManager([sheet sheetWindow],
-                                 std::move(native_manager));
+  native_manager_.reset(
+      new SingleWebContentsDialogManagerCocoa(this, sheet_.get(),
+                                              GetDialogManager()));
 }
 
 ConstrainedWindowMac::~ConstrainedWindowMac() {
   CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  native_manager_.reset();
   DCHECK(!manager_);
 }
 
+void ConstrainedWindowMac::ShowWebContentsModalDialog() {
+  scoped_ptr<SingleWebContentsDialogManagerCocoa> dialog_manager;
+  dialog_manager.reset(native_manager_.release());
+  GetDialogManager()->ShowDialogWithManager(
+      [sheet_.get() sheetWindow], std::move(dialog_manager));
+}
+
 void ConstrainedWindowMac::CloseWebContentsModalDialog() {
   if (manager_)
     manager_->Close();
@@ -49,3 +73,13 @@ void ConstrainedWindowMac::OnDialogClosing() {
   if (delegate_)
     delegate_->OnConstrainedWindowClosed(this);
 }
+
+bool ConstrainedWindowMac::DialogWasShown() {
+  // If the dialog was shown, |native_manager_| would have been released.
+  return !native_manager_;
+}
+
+WebContentsModalDialogManager* ConstrainedWindowMac::GetDialogManager() {
+  DCHECK(web_contents_);
+  return WebContentsModalDialogManager::FromWebContents(web_contents_);
+}