Enable AutoResize for Constrained Web Dialogs for Mac.

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

Index: chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.h
diff --git a/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.h b/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.h
index e3d981edd473d5ba63b33dffd050956c2b3e3fe3..588b35e7cec21e2c5ebfb9a15604640df8be9988 100644
--- a/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.h
+++ b/chrome/browser/ui/cocoa/constrained_window/constrained_window_mac.h
@@ -7,6 +7,9 @@
 
 #import <Cocoa/Cocoa.h>
 
+#include "base/mac/scoped_nsobject.h"
+#include "components/web_modal/web_contents_modal_dialog_manager.h"
+
 namespace content {
 class WebContents;
 }
@@ -21,6 +24,18 @@ class ConstrainedWindowMacDelegate {
   virtual void OnConstrainedWindowClosed(ConstrainedWindowMac* window) = 0;
 };
 
+// Creates a ConstrainedWindowMac, shows the dialog, and returns it.
+ConstrainedWindowMac* CreateAndShowWebModalDialogMac(
+    ConstrainedWindowMacDelegate* delegate,
+    content::WebContents* web_contents,
+    id<ConstrainedWindowSheet> sheet);
+
+// Creates a ConstrainedWindowMac and returns it.
+ConstrainedWindowMac* CreateWebModalDialogMac(
+    ConstrainedWindowMacDelegate* delegate,
+    content::WebContents* web_contents,
+    id<ConstrainedWindowSheet> sheet);
+
 // Constrained window implementation for Mac.
 // Normally an instance of this class is owned by the delegate. The delegate
 // should delete the instance when the window is closed.
@@ -31,6 +46,9 @@ class ConstrainedWindowMac {
                        id<ConstrainedWindowSheet> sheet);
   ~ConstrainedWindowMac();
 
+  // Shows the constrained window.
+  void ShowWebContentsModalDialog();
+
   // Closes the constrained window.
   void CloseWebContentsModalDialog();
 
@@ -38,13 +56,20 @@ class ConstrainedWindowMac {
   void set_manager(SingleWebContentsDialogManagerCocoa* manager) {
     manager_ = manager;
   }
+  id<ConstrainedWindowSheet> sheet() const { return sheet_.get(); }
 
   // Called by |manager_| when the dialog is closing.
   void OnDialogClosing();
 
+  // Gets the dialog manager for |web_contents_|.
+  web_modal::WebContentsModalDialogManager* GetDialogManager();
+
  private:
   ConstrainedWindowMacDelegate* delegate_;  // weak, owns us.
   SingleWebContentsDialogManagerCocoa* manager_;  // weak, owned by WCMDM.
+  content::WebContents* web_contents_;  // weak, owned by dialog initiator.
+  base::scoped_nsobject<id> sheet_;

[erikchen, 2015/11/12 22:14:57]

using scoped_nsprotocol should allow you to retain type information
(ConstrainedWindowSheet), whereas an id is more like a void pointer. 

[apacible, 2015/11/13 00:04:00]

Done.

+  scoped_ptr<SingleWebContentsDialogManagerCocoa> native_manager_;
 };
 
 #endif  // CHROME_BROWSER_UI_COCOA_CONSTRAINED_WINDOW_CONSTRAINED_WINDOW_MAC_