Introduce the abstract class WebViewBase, to decouple WebViewImpl.

third_party/WebKit/Source/web/WebAXObject.cpp

Index: third_party/WebKit/Source/web/WebAXObject.cpp
diff --git a/third_party/WebKit/Source/web/WebAXObject.cpp b/third_party/WebKit/Source/web/WebAXObject.cpp
index 71831f744a4404d51f3e72e9f0dd6ba1a52d6fe8..bef659ec43a29ade90ee9f96daeb1497adc3b68e 100644
--- a/third_party/WebKit/Source/web/WebAXObject.cpp
+++ b/third_party/WebKit/Source/web/WebAXObject.cpp
@@ -36,6 +36,7 @@
 #include "core/dom/Document.h"
 #include "core/dom/Node.h"
 #include "core/editing/markers/DocumentMarker.h"
+#include "core/exported/WebViewBase.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/VisualViewport.h"
 #include "core/input/KeyboardEventManager.h"
@@ -57,7 +58,6 @@
 #include "public/web/WebElement.h"
 #include "public/web/WebNode.h"
 #include "web/WebLocalFrameImpl.h"
-#include "web/WebViewImpl.h"
 
 namespace blink {
 
@@ -944,7 +944,7 @@ void WebAXObject::ShowContextMenu() const {
   if (!frame)
     return;
 
-  WebViewImpl* view = WebLocalFrameImpl::FromFrame(frame)->ViewImpl();
+  WebViewBase* view = WebLocalFrameImpl::FromFrame(frame)->ViewImpl();
   if (!view)
     return;