Introduce ManifestUpgradeDetector for WebAPK to detect web manifest changes.

chrome/browser/android/webapps/manifest_upgrade_detector.h

+// Copyright 2016 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_WEBAPPS_MANIFEST_UPGRADE_DETECTOR_H_
+#define CHROME_BROWSER_ANDROID_WEBAPPS_MANIFEST_UPGRADE_DETECTOR_H_
+
+#include <vector>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_weak_ref.h"
+#include "base/macros.h"
+#include "chrome/browser/android/shortcut_info.h"
+#include "chrome/browser/android/webapps/add_to_homescreen_data_fetcher.h"
+#include "content/public/common/manifest.h"
+
+namespace content {
+class WebContents;
+}  // namespace content
+
+namespace IPC {
+class Message;
+}
+
+class GURL;
+
+// ManifestUpgradeDetector is the C++ counterpart of
+// org.chromium.chrome.browser's ManifestUpgradeDetector in Java. The object
+// is owned by the Java object. It is created from there via a JNI (Initialize)
+// call and MUST BE DESTROYED via Destroy().
+class ManifestUpgradeDetector :
+    public content::WebContentsObserver,
+    public AddToHomescreenDataFetcher::Observer {
+ public:
+  ManifestUpgradeDetector(JNIEnv* env,
+                          jobject obj,
+                          content::WebContents* web_contents);
+
+  // Observes a new WebContents, if necessary.
+  void ReplaceWebContents(
+      JNIEnv* env,
+      const base::android::JavaParamRef<jobject>& obj,
+      const base::android::JavaParamRef<jobject>& jweb_contents);
+
+  // Called by the Java counterpart to destroy its native half.
+  void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+
+  // Called by the Java counterpart to start checking web manifest changes.
+  void Start(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
+
+  // Registers JNI hooks.
+  static bool Register(JNIEnv* env);
+
+  // AddToHomescreenDataFetcher::Observer.
+  void OnDidHasManifest(bool has_manifest) override;
+  void OnDataAvailable(const ShortcutInfo& info,
+                       const SkBitmap& icon,
+                       const std::vector<std::string>& icon_urls) override;
+  void OnUserTitleAvailable(const base::string16& user_title) override {}
+  SkBitmap FinalizeLauncherIcon(const SkBitmap& icon,
+                                const GURL& url,
+                                bool* is_generated) override;
+ private:
+  ~ManifestUpgradeDetector() override;
+
+  // content::WebContentsObserver.
+  void DidFinishLoad(content::RenderFrameHost* render_frame_host,
+                     const GURL& validated_url) override;
+
+  void RequestDetector(const GURL& validated_url);
+
+  AddToHomescreenDataFetcher* CreateDataFetcher();
+
+  // Points to the Java object.
+  base::android::ScopedJavaGlobalRef<jobject> java_ref_;
+
+  bool start_fetching_;
+
+  // Fetches data required to add a shortcut.
+  scoped_refptr<AddToHomescreenDataFetcher> data_fetcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(ManifestUpgradeDetector);
+};
+
+#endif  // CHROME_BROWSER_ANDROID_WEBAPPS_MANIFEST_UPGRADE_DETECTOR_H_