Switch the inheritance of WebView from WebWidget to protected.

third_party/WebKit/public/web/WebLocalFrame.h

Index: third_party/WebKit/public/web/WebLocalFrame.h
diff --git a/third_party/WebKit/public/web/WebLocalFrame.h b/third_party/WebKit/public/web/WebLocalFrame.h
index 88eaf2778114cb69cc7b48044b0c466e8a986725..1b47bdfa652ead547059ffba359dc912d5970c47 100644
--- a/third_party/WebKit/public/web/WebLocalFrame.h
+++ b/third_party/WebKit/public/web/WebLocalFrame.h
@@ -18,6 +18,7 @@ class WebFrameClient;
 class WebNode;
 class WebScriptExecutionCallback;
 class WebSuspendableTask;
+class WebWidget;
 enum class WebAppBannerPromptReply;
 enum class WebCachePolicy;
 enum class WebSandboxFlags;
@@ -316,6 +317,10 @@ public:
     // Returns the node that the context menu opened over.
     virtual WebNode contextMenuNode() const = 0;
 
+    // Returns the WebFrameWidget associated with this frame if there is one or
+    // nullptr otherwise.
+    virtual WebWidget* frameWidget() const = 0;
+
 protected:
     explicit WebLocalFrame(WebTreeScopeType scope) : WebFrame(scope) { }