Check for null return from GetNativeView().

chrome/browser/ui/ash/chrome_keyboard_ui.cc

Index: chrome/browser/ui/ash/chrome_keyboard_ui.cc
diff --git a/chrome/browser/ui/ash/chrome_keyboard_ui.cc b/chrome/browser/ui/ash/chrome_keyboard_ui.cc
index 1128f6ae93c9cc5ca2ebbdbd89e3a4e859ce571d..d7aafc7821e8eb4744bdaec8dfbda98a1f0f0f66 100644
--- a/chrome/browser/ui/ash/chrome_keyboard_ui.cc
+++ b/chrome/browser/ui/ash/chrome_keyboard_ui.cc
@@ -183,6 +183,12 @@ void ChromeKeyboardUI::ShowKeyboardContainer(aura::Window* container) {
 }
 
 bool ChromeKeyboardUI::ShouldWindowOverscroll(aura::Window* window) const {
+  // Added while we determine if RenderWidgetHostViewChildFrame can be changed
+  // to always return a non-null value: https://crbug.com/644726 .
+  // If we cannot always return a non-null value, then this may need to stay.
+  if (!window)
+    return true;

[Charlie Reis, 2016/09/07 17:23:58]

I would suggest putting the null check in KeyboardUIContent::InitInsets instead.
 There's another caller of ShouldWindowOverscroll which passes
GetContainerWindow instead of GetNativeView, and we wouldn't want to paper over
a bug there if there was one.

[wjmaclean, 2016/09/07 17:41:05]

Done.

I also added a check in UpdateInsetsForWindow(), which is also a caller of
ShouldWindowOverscroll(), even though it seems less likely to be directly called
with a window* obtained from GetNativeView().

+
   aura::Window* root_window = window->GetRootWindow();
   if (!root_window)
     return true;