Add calls to the server to request WebAPK updates.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..f378373644a20036fc56b1494efdcfc3372cfc4b
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkUpdateManager.java
@@ -0,0 +1,144 @@
+// 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.
+
+package org.chromium.chrome.browser.webapps;
+
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.graphics.Bitmap;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.webapps.WebappRegistry.FetchWebappDataStorageCallback;
+import org.chromium.webapk.lib.common.WebApkConstants;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * WebApkUpdateManager manages when to check for updates to the WebAPK's Web Manifest, and sends

[pkotwicz, 2016/08/11 22:02:43]

Nit: "sends update request" -> "sends an update request"

[Xi Han, 2016/08/15 21:38:45]

Done.

+ * update request to the WebAPK Server when an update is needed.
+ */
+public class WebApkUpdateManager implements ManifestUpgradeDetector.CheckIfUpgradeNeededCallback {
+    /** Number of milliseconds between checks for whether the WebAPK's Web Manifest has changed. */
+    static final long FULL_CHECK_UPDATE_INTERVAL = TimeUnit.DAYS.toMillis(3L);
+
+    /**
+     * Number of milliseconds to wait before re-requesting an updated WebAPK from the WebAPK
+     * server if the previous update attempt failed.
+     */
+    static final long RETRY_UPDATE_DURATION = TimeUnit.HOURS.toMillis(12L);
+
+    private ManifestUpgradeDetector mUpgradeDetector;
+
+    /**
+     * Checks whether the WebAPK's Web Manifest has changed. Requests an updated WebAPK if the
+     * Web Manifest has changed. Skips the check if the check was done recently.
+     * @param tab  The tab of the WebAPK.
+     * @param info The WebappInfo of the WebAPK.
+     */
+    public void checkIfUpdateNeeded(Tab tab, WebappInfo info) {
+        ThreadUtils.assertOnUiThread();

[pkotwicz, 2016/08/11 22:02:43]

I am stupid. I thought that checkIfUpdateNeeded() would run on a background
thread but it does not. If everything runs on a background thread, you don't
need the asserts

[Xi Han, 2016/08/15 21:38:44]

Removed.

+
+        mUpgradeDetector = new ManifestUpgradeDetector(tab, info, this);
+
+        WebappRegistry.getWebappDataStorage(ContextUtils.getApplicationContext(), info.id(),
+                new WebappRegistry.FetchWebappDataStorageCallback() {
+                    @Override
+                    public void onWebappDataStorageRetrieved(WebappDataStorage storage) {
+                        if (storage == null) {
+                            startUpdateCheck(storage);
+                            return;
+                        }
+
+                        long sinceLastCheckDuration = System.currentTimeMillis()
+                                - storage.getLastCheckForWebManifestUpdateTime();
+                        long sinceLastRequestDuration = System.currentTimeMillis()
+                                - storage.getLastWebApkUpdateRequestCompletionTime();
+                        if (sinceLastCheckDuration > FULL_CHECK_UPDATE_INTERVAL
+                                || (sinceLastRequestDuration > RETRY_UPDATE_DURATION
+                                && !storage.getDoesLastWebApkUpdateRequestSucceed())) {
+                            startUpdateCheck(storage);
+                        }
+                    }
+                });
+    }
+
+    private void startUpdateCheck(WebappDataStorage storage) {
+        ThreadUtils.assertOnUiThread();

[pkotwicz, 2016/08/11 22:02:43]

I don't think that this assert is useful

[Xi Han, 2016/08/15 21:38:45]

Done.

+
+        if (mUpgradeDetector.isWebContentsGone()) return;

[Yaron, 2016/08/12 21:16:17]

How about:
if (upgradeDetector.start()) {
   storage.updateTimeOfLastCheckForUpdatedWebManifest();
}

(i.e. merge the two functions)

[Xi Han, 2016/08/15 21:38:44]

Done.

+
+        // crbug.com/636525. The timestamp of the last check for updated Web Manifest should
+        // be updated after the detector finds the Web Manifest, not when the detector is started.
+        storage.updateTimeOfLastCheckForUpdatedWebManifest();

[Yaron, 2016/08/12 21:16:16]

this will still NPE in the first case of storage == null (L51)

[Xi Han, 2016/08/15 21:38:45]

Miss this part in last round, good catch. I think your previous commends make
sense, it seems it is impossible that the storage is null. Remove the storage ==
null case.

+        mUpgradeDetector.start();
+    }
+
+    @Override
+    public void onCheckIfUpdateNeededFinished(boolean isUpgraded, WebappInfo newInfo) {

[Yaron, 2016/08/12 21:16:16]

s/isUpgraded/needsUpgrade/

[Xi Han, 2016/08/15 21:38:44]

Done.

+        if (isUpgraded) {
+            updateAsync(newInfo);
+        }
+        mUpgradeDetector.destroy();
+        mUpgradeDetector = null;
+    }
+
+    /**
+     * Sends request to WebAPK Server to update WebAPK.
+     * @param webappInfo The new fetched Web Manifest data of the WebAPK.
+     */
+    public void updateAsync(WebappInfo webappInfo) {
+        int webApkVersion = getVersionFromMetaData(webappInfo.webApkPackageName());
+        nativeUpdateAsync(webappInfo.uri().toString(), webappInfo.scopeUri().toString(),
+                webappInfo.name(), webappInfo.shortName(), "", webappInfo.icon(),
+                webappInfo.displayMode(), webappInfo.orientation(), webappInfo.themeColor(),
+                webappInfo.backgroundColor(), webappInfo.webManifestUri().toString(),
+                webappInfo.webApkPackageName(), webApkVersion);
+    }
+
+    public void destroy() {
+        if (mUpgradeDetector != null) {
+            mUpgradeDetector.destroy();
+        }
+        mUpgradeDetector = null;
+    }
+
+    private static int getVersionFromMetaData(String webApkPackage) {
+        try {
+            PackageManager packageManager =
+                    ContextUtils.getApplicationContext().getPackageManager();
+            PackageInfo info = packageManager.getPackageInfo(webApkPackage, 0);
+            return info.versionCode;
+        } catch (PackageManager.NameNotFoundException e) {
+            e.printStackTrace();
+        }
+        return 1;
+    }
+
+    /**
+     * Called after the either a request to update the WebAPK has been sent or the update process

[pkotwicz, 2016/08/11 22:02:43]

Nit: "the either" -> "either"

[Xi Han, 2016/08/15 21:38:45]

Done.

+     * fails.
+     */
+    @CalledByNative
+    public static void onBuiltWebApk(final boolean success, String webapkPackage) {

[Yaron, 2016/08/12 21:16:16]

make private if only called by native

[Xi Han, 2016/08/15 21:38:45]

Done.

+        WebappRegistry.getWebappDataStorage(ContextUtils.getApplicationContext(),
+                WebApkConstants.WEBAPK_ID_PREFIX + webapkPackage,
+                new FetchWebappDataStorageCallback() {
+                    @Override
+                    public void onWebappDataStorageRetrieved(WebappDataStorage storage) {
+                        // Update the request time and result together. It prevents getting a
+                        // correct request time but a result from the previous request.
+                        storage.updateTimeOfLastWebApkUpdateRequestCompletion();
+                        storage.updateDoesLastWebApkUpdateRequestSucceed(success);
+                    }
+                });
+    }
+
+    private static native void nativeUpdateAsync(String startUrl, String scope, String name,
+            String shortName, String iconUrl, Bitmap icon, int displayMode, int orientation,
+            long themeColor, long backgroundColor, String manifestUrl, String webApkPackage,
+            int webApkVersion);
+}