Refactor Autofill for OOPIF, step 1: add autofillClient to WebLocalFrame

public/web/WebLocalFrame.h

Index: public/web/WebLocalFrame.h
diff --git a/public/web/WebLocalFrame.h b/public/web/WebLocalFrame.h
index 97bf5123260f799747c6c22009e42f4574b118b3..71dc1ac0c511274f32c42ddcc130164ec3297b2f 100644
--- a/public/web/WebLocalFrame.h
+++ b/public/web/WebLocalFrame.h
@@ -9,6 +9,7 @@
 
 namespace blink {
 
+class WebAutofillClient;
 class WebScriptExecutionCallback;
 struct WebPrintPresetOptions;
 
@@ -42,6 +43,8 @@ public:
     // swapped into the frame tree if it commits.
     virtual void initializeToReplaceRemoteFrame(WebRemoteFrame*) = 0;
 
+    virtual void setAutofillClient(WebAutofillClient*) = 0;
+
 
     // Navigation Ping --------------------------------------------------------
     virtual void sendPings(const WebNode& linkNode, const WebURL& destinationURL) = 0;