Remove some TabContentses from extensions.

chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_api.cc

Index: chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_api.cc
diff --git a/chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_api.cc b/chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_api.cc
index 3a0803d87cf9b0294aa0f76ae835f8caea0b2117..fe4cb750a77c34e835b5c42391c1cd13ce4efdcf 100644
--- a/chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_api.cc
+++ b/chrome/browser/extensions/api/offscreen_tabs/offscreen_tabs_api.cc
@@ -807,7 +807,7 @@ bool UpdateOffscreenTabFunction::RunImpl() {
   DictionaryValue* update_props;
   EXTENSION_FUNCTION_VALIDATE(args_->GetDictionary(1, &update_props));
 
-  tab_contents_ = offscreen_tab->tab_contents();
+  web_contents_ = offscreen_tab->tab_contents()->web_contents();
   bool is_async = false;
   if (!UpdateURLIfPresent(update_props, offscreen_tab_id, &is_async))
     return false;
@@ -815,8 +815,7 @@ bool UpdateOffscreenTabFunction::RunImpl() {
   // Update the width and height, if specified.
   if (update_props->HasKey(tabs_keys::kWidthKey) ||
       update_props->HasKey(tabs_keys::kHeightKey)) {
-    const gfx::Size& size =
-        tab_contents_->web_contents()->GetView()->GetContainerSize();
+    const gfx::Size& size = web_contents_->GetView()->GetContainerSize();
 
     int width;
     if (update_props->HasKey(tabs_keys::kWidthKey))