[Profile creation] Support webauthn in the sign-in flow

This CL adds WebContentsModalDialogManager to the sign-in flow web
contents and implements its delegates. This is needed by the webauthn
modal dialog which is in turn needed by the Gaia sign-in flow with
security keys.

Bug: 1167887
Change-Id: Ief107bf16056c5a8ceb3ed7b192b22497957e09c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2636399
Commit-Queue: David Roger <droger@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844696}

chrome/browser/ui/views/profiles/profile_picker_view.cc

@@ -54,6 +54,7 @@
 #include "components/signin/public/identity_manager/account_info.h"
 #include "components/startup_metric_utils/browser/startup_metric_utils.h"
 #include "components/vector_icons/vector_icons.h"
+#include "components/web_modal/web_contents_modal_dialog_manager.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/context_menu_params.h"
 #include "content/public/browser/render_frame_host.h"
@@ -524,6 +525,13 @@ void ProfilePickerView::OnProfileForSigninCreated(
       content::WebContents::CreateParams(signed_in_profile_being_created_));
   new_profile_contents_->SetDelegate(this);
 
+  // Create a manager that supports modal dialogs, such as for webauthn.
+  web_modal::WebContentsModalDialogManager::CreateForWebContents(
+      new_profile_contents_.get());
+  web_modal::WebContentsModalDialogManager::FromWebContents(
+      new_profile_contents_.get())
+      ->SetDelegate(this);
+
   // Make sure the web contents used for sign-in has proper background to match
   // the toolbar (for dark mode).
   views::WebContentsSetBackgroundColor::CreateForWebContentsWithColor(
@@ -819,6 +827,30 @@ void ProfilePickerView::OnExtendedAccountInfoUpdated(
   extended_account_info_timeout_closure_.Cancel();
 }
 
+web_modal::WebContentsModalDialogHost*
+ProfilePickerView::GetWebContentsModalDialogHost() {
+  return this;
+}
+
+gfx::NativeView ProfilePickerView::GetHostView() const {
+  return GetWidget()->GetNativeView();
+}
+
+gfx::Point ProfilePickerView::GetDialogPosition(const gfx::Size& size) {
+  gfx::Size widget_size = GetWidget()->GetWindowBoundsInScreen().size();
+  return gfx::Point(std::max(0, (widget_size.width() - size.width()) / 2), 0);
+}
+
+gfx::Size ProfilePickerView::GetMaximumDialogSize() {
+  return GetWidget()->GetWindowBoundsInScreen().size();
+}
+
+void ProfilePickerView::AddObserver(
+    web_modal::ModalDialogHostObserver* observer) {}
+
+void ProfilePickerView::RemoveObserver(
+    web_modal::ModalDialogHostObserver* observer) {}
+
 void ProfilePickerView::SetExtendedAccountInfoTimeoutForTesting(
     base::TimeDelta timeout) {
   extended_account_info_timeout_ = timeout;

chrome/browser/ui/views/profiles/profile_picker_view.h

@@ -8,10 +8,12 @@
 #include "base/cancelable_callback.h"
 #include "base/time/time.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/chrome_web_modal_dialog_manager_delegate.h"
 #include "chrome/browser/ui/profile_picker.h"
 #include "chrome/browser/ui/views/profiles/user_manager_profile_dialog_host.h"
 #include "components/keep_alive_registry/scoped_keep_alive.h"
 #include "components/signin/public/identity_manager/identity_manager.h"
+#include "components/web_modal/web_contents_modal_dialog_host.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "ui/views/controls/webview/unhandled_keyboard_event_handler.h"
 #include "ui/views/controls/webview/webview.h"
@@ -34,7 +36,9 @@ class WebContents;
 // Dialog widget that contains the Desktop Profile picker webui.
 class ProfilePickerView : public views::WidgetDelegateView,
                           public content::WebContentsDelegate,
-                          public signin::IdentityManager::Observer {
+                          public signin::IdentityManager::Observer,
+                          public ChromeWebModalDialogManagerDelegate,
+                          public web_modal::WebContentsModalDialogHost {
  public:
   using BrowserOpenedCallback = base::OnceCallback<void(Browser*)>;
 
@@ -108,6 +112,17 @@ class ProfilePickerView : public views::WidgetDelegateView,
       const CoreAccountInfo& account_info) override;
   void OnExtendedAccountInfoUpdated(const AccountInfo& account_info) override;
 
+  // ChromeWebModalDialogManagerDelegate
+  web_modal::WebContentsModalDialogHost* GetWebContentsModalDialogHost()
+      override;
+
+  // web_modal::WebContentsModalDialogHost
+  gfx::NativeView GetHostView() const override;
+  gfx::Point GetDialogPosition(const gfx::Size& size) override;
+  gfx::Size GetMaximumDialogSize() override;
+  void AddObserver(web_modal::ModalDialogHostObserver* observer) override;
+  void RemoveObserver(web_modal::ModalDialogHostObserver* observer) override;
+
   // Builds the views hieararchy.
   void BuildLayout();