Use explicit WebString conversions in plugins code

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 128 matching lines @@
   if (finished_loading_)
     UpdateMessage();
 }
 
 void LoadablePluginPlaceholder::UpdateMessage() {
   if (!plugin())
     return;
   std::string script =
       "window.setMessage(" + base::GetQuotedJSONString(message_) + ")";
   plugin()->web_view()->mainFrame()->executeScript(
-      blink::WebScriptSource(base::UTF8ToUTF16(script)));
+      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;
     } else if (is_blocked_for_power_saver_poster_) {
@@ skipping 79 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::WebScriptSource(base::UTF8ToUTF16(script)));
+        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 104 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