Introduce the abstract class WebViewBase, to decouple WebViewImpl.

third_party/WebKit/Source/web/WebDevToolsAgentImpl.cpp

Index: third_party/WebKit/Source/web/WebDevToolsAgentImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebDevToolsAgentImpl.cpp b/third_party/WebKit/Source/web/WebDevToolsAgentImpl.cpp
index 0254a0ccb6f7788ede9d6be74271b9951290ca9f..5b9449cb185a247d0af235833dd6c3875b1856d3 100644
--- a/third_party/WebKit/Source/web/WebDevToolsAgentImpl.cpp
+++ b/third_party/WebKit/Source/web/WebDevToolsAgentImpl.cpp
@@ -36,6 +36,7 @@
 #include "bindings/core/v8/ScriptController.h"
 #include "bindings/core/v8/V8BindingForCore.h"
 #include "core/CoreProbeSink.h"
+#include "core/exported/WebViewBase.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
@@ -89,7 +90,6 @@
 #include "web/WebInputEventConversion.h"
 #include "web/WebLocalFrameImpl.h"
 #include "web/WebSettingsImpl.h"
-#include "web/WebViewImpl.h"
 
 namespace blink {
 
@@ -241,7 +241,7 @@ WebDevToolsAgentImpl* WebDevToolsAgentImpl::Create(
     return agent;
   }
 
-  WebViewImpl* view = frame->ViewImpl();
+  WebViewBase* view = frame->ViewImpl();
   WebDevToolsAgentImpl* agent = new WebDevToolsAgentImpl(frame, client, true);
   agent->LayerTreeViewChanged(view->LayerTreeView());
   return agent;