Check CanCallJavaScriptFunction() in SharedPasswordController

The check was there before, but I accidentally removed it as part of
the refactoring in:
https://chromium-review.googlesource.com/c/chromium/src/+/2254351

Change-Id: I4c57334ead28dd94fa624656b6fc21041bb10a1d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2310845
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Reviewed-by: Mohamed Amir Yosef <mamir@chromium.org>
Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Reviewed-by: Maria Kazinova <kazinova@google.com>
Cr-Commit-Position: refs/heads/master@{#790948}

components/password_manager/ios/shared_password_controller.mm

@@ -213,6 +213,8 @@ NSString* const kSuggestionSuffix = @" ••••••••";
     frameDidBecomeAvailable:(web::WebFrame*)web_frame {
   DCHECK_EQ(_webState, webState);
   DCHECK(web_frame);
+  if (!web_frame->CanCallJavaScriptFunction())
+    return;
   UniqueIDTabHelper* uniqueIDTabHelper =
       UniqueIDTabHelper::FromWebState(_webState);
   uint32_t nextAvailableRendererID =