Http Bad: Add "Learn more" sublabel to warning message and make it clickable

chrome/browser/ui/autofill/chrome_autofill_client.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_AUTOFILL_CHROME_AUTOFILL_CLIENT_H_
 #define CHROME_BROWSER_UI_AUTOFILL_CHROME_AUTOFILL_CLIENT_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 62 matching lines @@
   bool IsAutocompleteEnabled() override;
   void PropagateAutofillPredictions(
       content::RenderFrameHost* rfh,
       const std::vector<autofill::FormStructure*>& forms) override;
   void DidFillOrPreviewField(const base::string16& autofilled_value,
                              const base::string16& profile_full_name) override;
   void OnFirstUserGestureObserved() override;
   bool IsContextSecure(const GURL& form_origin) override;
   bool ShouldShowSigninPromo() override;
   void StartSigninFlow() override;
+  void ShowHttpNotSecureExplanation() override;
 
   // content::WebContentsObserver implementation.
   void MainFrameWasResized(bool width_changed) override;
   void WebContentsDestroyed() override;
 
   // ZoomObserver implementation.
   void OnZoomChanged(
       const zoom::ZoomController::ZoomChangedEventData& data) override;
 
  private:
   explicit ChromeAutofillClient(content::WebContents* web_contents);
   friend class content::WebContentsUserData<ChromeAutofillClient>;
 
   base::WeakPtr<AutofillPopupControllerImpl> popup_controller_;
   CardUnmaskPromptControllerImpl unmask_controller_;
 
   // The identity provider, used for Payments integration.
   std::unique_ptr<IdentityProvider> identity_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeAutofillClient);
 };
 
 }  // namespace autofill
 
 #endif  // CHROME_BROWSER_UI_AUTOFILL_CHROME_AUTOFILL_CLIENT_H_