[signin] Add ScopedKeepAlive to ProfilePickerView

This prevents Chrome from shutting down while the profile picker is
displayed.

Fixed: 1119369
Change-Id: I1d9df7c66c360dd29984876382b116d5732cb132
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2375350Reviewed-by: Monica Basta <msalama@chromium.org>
Commit-Queue: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801694}

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

@@ -16,6 +16,7 @@
 #include "chrome/common/webui_url_constants.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/google_chrome_strings.h"
+#include "components/keep_alive_registry/keep_alive_types.h"
 #include "content/public/browser/context_menu_params.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_widget_host_view.h"
@@ -64,7 +65,8 @@ void ProfilePicker::Hide() {
 }
 
 ProfilePickerView::ProfilePickerView()
-    : web_view_(nullptr), initialized_(InitState::kNotInitialized) {
+    : keep_alive_(KeepAliveOrigin::USER_MANAGER_VIEW,
+                  KeepAliveRestartOption::DISABLED) {
   SetHasWindowSizeControls(true);
   SetButtons(ui::DIALOG_BUTTON_NONE);
   SetTitle(IDS_PRODUCT_NAME);

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

@@ -7,6 +7,7 @@
 
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/profile_picker.h"
+#include "components/keep_alive_registry/scoped_keep_alive.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "ui/views/controls/webview/webview.h"
 #include "ui/views/window/dialog_delegate.h"
@@ -56,8 +57,9 @@ class ProfilePickerView : public views::DialogDelegateView,
   bool HandleContextMenu(content::RenderFrameHost* render_frame_host,
                          const content::ContextMenuParams& params) override;
 
-  views::WebView* web_view_;
-  InitState initialized_;
+  ScopedKeepAlive keep_alive_;
+  views::WebView* web_view_ = nullptr;
+  InitState initialized_ = InitState::kNotInitialized;
   base::WeakPtrFactory<ProfilePickerView> weak_ptr_factory_{this};
 
   DISALLOW_COPY_AND_ASSIGN(ProfilePickerView);