Track where WebContents are created in order to better understand issue.

ui/keyboard/content/keyboard_ui_content.cc

Index: ui/keyboard/content/keyboard_ui_content.cc
diff --git a/ui/keyboard/content/keyboard_ui_content.cc b/ui/keyboard/content/keyboard_ui_content.cc
index 5a317294890c57e1dd3d117afc24d5433a5f2232..d0f3ac88845af8bdc63e4b7ce72dd45fe9d0fd61 100644
--- a/ui/keyboard/content/keyboard_ui_content.cc
+++ b/ui/keyboard/content/keyboard_ui_content.cc
@@ -11,9 +11,9 @@
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_source.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/common/bindings_policy.h"
 #include "ui/aura/layout_manager.h"
@@ -189,6 +189,8 @@ aura::Window* KeyboardUIContent::GetKeyboardWindow() {
         content::WebContents::CreateParams(context,
             content::SiteInstance::CreateForURL(context,
                                                 GetVirtualKeyboardUrl()))));
+    WebContentsSource::CreateForWebContentsAndLocation(keyboard_contents_.get(),
+                                                       FROM_HERE);
     keyboard_contents_->SetDelegate(new KeyboardContentsDelegate(this));
     SetupWebContents(keyboard_contents_.get());
     LoadContents(GetVirtualKeyboardUrl());