Move ExecuteScript method from WebFrame to WebLocalFrame.

components/plugins/renderer/loadable_plugin_placeholder.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/plugins/renderer/loadable_plugin_placeholder.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 127 matching lines @@
   message_ = message;
   if (finished_loading_)
     UpdateMessage();
 }
 
 void LoadablePluginPlaceholder::UpdateMessage() {
   if (!plugin())
     return;
   std::string script =
       "window.setMessage(" + base::GetQuotedJSONString(message_) + ")";
-  plugin()->web_view()->MainFrame()->ExecuteScript(
+  blink::WebFrame* main_frame = plugin()->web_view()->MainFrame();
+  if (!main_frame->IsWebLocalFrame()) {

[dcheng, 2017/06/04 10:37:22]

As this is a WebViewPlugin, which is only used to load very simple content for
the plugin placeholder, we should be able to just
DCHECK(main_frame->IsWebLocalFrame()) here.

(One possibility to make this clear is to directly expose a main_frame() helper
on WebViewPlugin that does the casting internally)

[Łukasz Anforowicz, 2017/06/05 17:10:57]

Good point - done:

- I've exposed WebViewPlugin::main_frame accessor that returns a local frame. 
This means that WebViewPlugin::web_view accessor can be made private.

- I've changed a few places to use the main_frame accessor, rather than call
ToWebLocalFrame, etc.

+    NOTREACHED();
+    return;
+  }
+  main_frame->ToWebLocalFrame()->ExecuteScript(
       blink::WebScriptSource(blink::WebString::FromUTF8(script)));
 }
 
 void LoadablePluginPlaceholder::PluginDestroyed() {
   if (power_saver_enabled_) {
     if (premade_throttler_) {
       // Since the premade plugin has been detached from the container, it will
       // not be automatically destroyed along with the page.
       premade_throttler_->GetWebPlugin()->Destroy();
       premade_throttler_ = nullptr;
@@ skipping 86 matching lines @@
       }
     }
   }
 
   if (is_blocked_for_power_saver_poster_) {
     // Adjust poster container padding and dimensions to center play button for
     // plugins and plugin posters that have their top or left portions obscured.
     std::string script = base::StringPrintf(
         "window.resizePoster('%dpx', '%dpx', '%dpx', '%dpx')", x, y, width,
         height);
-    plugin()->web_view()->MainFrame()->ExecuteScript(
+    blink::WebFrame* main_frame = plugin()->web_view()->MainFrame();
+    if (!main_frame->IsWebLocalFrame()) {
+      NOTREACHED();
+      return;
+    }
+    main_frame->ToWebLocalFrame()->ExecuteScript(
         blink::WebScriptSource(blink::WebString::FromUTF8(script)));
   }
 }
 
 void LoadablePluginPlaceholder::WasShown() {
   if (is_blocked_for_background_tab_) {
     is_blocked_for_background_tab_ = false;
     if (!LoadingBlocked())
       LoadPlugin();
   }
@@ skipping 108 matching lines @@
   return identifier_;
 }
 
 bool LoadablePluginPlaceholder::LoadingBlocked() const {
   DCHECK(allow_loading_);
   return is_blocked_for_tinyness_ || is_blocked_for_background_tab_ ||
          is_blocked_for_power_saver_poster_ || is_blocked_for_prerendering_;
 }
 
 }  // namespace plugins