kiosk: Fix zoom crash regression.

chrome/browser/ui/apps/chrome_app_delegate.cc

Index: chrome/browser/ui/apps/chrome_app_delegate.cc
diff --git a/chrome/browser/ui/apps/chrome_app_delegate.cc b/chrome/browser/ui/apps/chrome_app_delegate.cc
index ace97d0134d7ea318d133759275886d383b95672..2cf0588a9e8e000aab4deada86947417c5984622 100644
--- a/chrome/browser/ui/apps/chrome_app_delegate.cc
+++ b/chrome/browser/ui/apps/chrome_app_delegate.cc
@@ -6,6 +6,7 @@
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/stringprintf.h"
+#include "chrome/browser/app_mode/app_mode_utils.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/chrome_extension_web_contents_observer.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
@@ -20,6 +21,7 @@
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/scoped_tabbed_browser_displayer.h"
 #include "chrome/browser/ui/web_contents_sizer.h"
+#include "chrome/browser/ui/zoom/zoom_controller.h"
 #include "chrome/common/extensions/chrome_extension_messages.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/notification_service.h"
@@ -175,6 +177,10 @@ void ChromeAppDelegate::InitWebContents(content::WebContents* web_contents) {
 #endif  // defined(ENABLE_PRINTING)
   extensions::ChromeExtensionWebContentsObserver::CreateForWebContents(
       web_contents);
+
+  // Kiosk app supports zooming.
+  if (chrome::IsRunningInForcedAppMode())
+    ZoomController::CreateForWebContents(web_contents);

[tapted, 2014/09/11 23:55:01]

Do you think it's worth adding something near the other "future proof kiosk
mode" DCHECK, at

https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...

e.g.

  // Ensure there is a ZoomController in kiosk mode, otherwise the processing
  // the accelerators will cause a crash.
  DCHECK(!is_kiosk_app_mode ||
      ZoomController::FromWebContents(web_view()->GetWebContents());

pretty sure the construction order will make it safe. It's just tricky to see
the link between the code here and registering accelerators in
chrome_native_app_window_views.

[xiyuan, 2014/09/12 00:45:27]

Sounds good. Added the DCHECK there.

Do you prefer to create ZoomController in ChromeNativeAppWindowViews to keep
relevant code closer?

 }
 
 void ChromeAppDelegate::ResizeWebContents(content::WebContents* web_contents,