[Autofill] Migrate ContentAutofillDriver<-->AutofillAgent IPCs to mojo.

components/autofill/content/renderer/autofill_agent.h

Index: components/autofill/content/renderer/autofill_agent.h
diff --git a/components/autofill/content/renderer/autofill_agent.h b/components/autofill/content/renderer/autofill_agent.h
index aaf357670086c8b8c2ed4e2be291121a47c4a5fe..e1d9032cfcb3ca96ca4806082ded4455f05d1bec 100644
--- a/components/autofill/content/renderer/autofill_agent.h
+++ b/components/autofill/content/renderer/autofill_agent.h
@@ -58,6 +58,12 @@ class AutofillAgent : public content::RenderFrameObserver,
 
   void BindRequest(mojom::AutofillAgentRequest request);
 
+  // mojom::AutofillAgent:
+  void FirstUserGestureObservedInTab() override;
+  void FillForm(int32_t id,
+                const FormData& form,
+                const FillFormCallback& callback) override;
+
  private:
   // Functor used as a simplified comparison function for FormData. Only
   // compares forms at a high level (notably name, origin, action).
@@ -155,13 +161,9 @@ class AutofillAgent : public content::RenderFrameObserver,
 
   void OnFieldTypePredictionsAvailable(
       const std::vector<FormDataPredictions>& forms);
-  void OnFillForm(int query_id, const FormData& form);
   void OnPing();
   void OnPreviewForm(int query_id, const FormData& form);
 
-  // mojom::AutofillAgent:
-  void FirstUserGestureObservedInTab() override;
-
   // For external Autofill selection.
   void OnClearForm();
   void OnClearPreviewedForm();