Allow only responsive websites to install as a web app on mobile.

chrome/browser/android/banners/app_banner_data_fetcher_android.h

 // Copyright 2015 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_ANDROID_BANNERS_APP_BANNER_DATA_FETCHER_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_DATA_FETCHER_ANDROID_H_
 
 #include "base/android/jni_android.h"
 #include "chrome/browser/banners/app_banner_data_fetcher.h"
 
 namespace banners {
 
 // Fetches data required to show a banner for the URL currently shown by the
 // WebContents.  Extends the regular fetch to add support for Android apps.
 class AppBannerDataFetcherAndroid : public AppBannerDataFetcher {
  public:
   AppBannerDataFetcherAndroid(
       content::WebContents* web_contents,
       base::WeakPtr<Delegate> weak_delegate,
       int ideal_icon_size);
 
   // Saves information about the Android app being promoted by the current page,
   // then continues the creation pipeline.
   bool ContinueFetching(const base::string16& app_title,
                         const std::string& app_package,
                         base::android::ScopedJavaLocalRef<jobject> app_data,
                         const GURL& image_url);
 
+  using AppBannerDataFetcher::OnMessageReceived;

[benwells, 2015/06/11 01:54:24]

Why do you have this?

[dominickn (DO NOT USE), 2015/06/11 03:32:12]

The parent class OnMessageReceived() has a different signature to the one in
this class. This using statement is needed so that the child class method
doesn't hide the parent class method (even though they take different
arguments). It crashes without this statement.

+
+  // WebContentsObserver override.
+  bool OnMessageReceived(const IPC::Message& message) override;

[benwells, 2015/06/11 01:54:24]

Do these overrides need to be public? Can they be protected or private instead?

[dominickn (DO NOT USE), 2015/06/11 03:32:12]

HandleWebApp should be protected (it's protected in the parent class). Thanks!

[benwells, 2015/06/15 04:14:59]

OnMessageReceived should also be protected or private. Nothing that knows of
this as an AppbannerDataFetcherAndroid should be calling this function, only
bits of the code that know of it as a WebContentsObserver.

+
+  // AppBannerDataFetcher override. Queries the site's meta viewport tag to
+  // detect whether it is responsive, and proceeds by calling the base class
+  // implementation.
+  void HandleWebApp(content::WebContents* web_contents) override;
+
  protected:
   ~AppBannerDataFetcherAndroid() override;
 
   std::string GetBannerType() override;
   std::string GetAppIdentifier() override;
   void ShowBanner(const SkBitmap* icon,
                   const base::string16& title) override;
 
  private:
+  void OnDidRetrieveMetaTagContent(bool success,
+                                   const std::string& tag_name,
+                                   const std::string& tag_content,
+                                   const GURL& expected_url);
+
   base::android::ScopedJavaGlobalRef<jobject> native_app_data_;
   std::string native_app_package_;
 
   DISALLOW_COPY_AND_ASSIGN(AppBannerDataFetcherAndroid);
 };
 
 }  // namespace banners
 
 #endif  // CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_DATA_FETCHER_ANDROID_H_