Introduce WebPluginContainerBase to abstract WebPluginContainerImpl.

third_party/WebKit/Source/web/WebHelperPluginImpl.cpp

Index: third_party/WebKit/Source/web/WebHelperPluginImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebHelperPluginImpl.cpp b/third_party/WebKit/Source/web/WebHelperPluginImpl.cpp
index 08269910dfd948e6d1abd33d72bc9b072e7dec2f..db3659067fd5e24c6092b9416a3840a04f243f1c 100644
--- a/third_party/WebKit/Source/web/WebHelperPluginImpl.cpp
+++ b/third_party/WebKit/Source/web/WebHelperPluginImpl.cpp
@@ -30,12 +30,12 @@
 
 #include "web/WebHelperPluginImpl.h"
 
+#include "core/exported/WebPluginContainerBase.h"
 #include "core/frame/LocalFrameClient.h"
 #include "core/frame/WebLocalFrameBase.h"
 #include "core/html/HTMLObjectElement.h"
 #include "core/loader/FrameLoader.h"
 #include "public/web/WebPlugin.h"
-#include "web/WebPluginContainerImpl.h"
 
 namespace blink {
 
@@ -64,7 +64,7 @@ bool WebHelperPluginImpl::Initialize(const String& plugin_type,
   Vector<String> attribute_names;
   Vector<String> attribute_values;
   DCHECK(frame->GetFrame()->GetDocument()->Url().IsValid());
-  plugin_container_ = ToWebPluginContainerImpl(
+  plugin_container_ = ToWebPluginContainerBase(
       frame->GetFrame()->Loader().Client()->CreatePlugin(
           object_element_.Get(), frame->GetFrame()->GetDocument()->Url(),
           attribute_names, attribute_values, plugin_type, false,