Add AwVariationsSeedFetcher and refactory VariationsSeedFetcher

android_webview/java/src/org/chromium/android_webview/AwVariationsSeedFetcher.java

Index: android_webview/java/src/org/chromium/android_webview/AwVariationsSeedFetcher.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwVariationsSeedFetcher.java b/android_webview/java/src/org/chromium/android_webview/AwVariationsSeedFetcher.java
new file mode 100644
index 0000000000000000000000000000000000000000..90c9a331f93c952098ffd8f30e6cd513e82e2af4
--- /dev/null
+++ b/android_webview/java/src/org/chromium/android_webview/AwVariationsSeedFetcher.java
@@ -0,0 +1,104 @@
+// Copyright 2017 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.android_webview;
+
+import android.content.Context;
+import android.os.SystemClock;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
+import org.chromium.components.variations.firstrun.VariationsSeedFetcher;
+
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+import java.net.SocketTimeoutException;
+import java.net.UnknownHostException;
+
+/**
+ * Fetches the variations seed in Java layer before Android WebView's native code runs.
+ */
+public class AwVariationsSeedFetcher {
+    private static final String TAG = "AwVariatnsSeedFetch";
+
+    private static final String SEED_DATA_FILENAME = "variations_seed";
+    private static final String SEED_DATA_PREF_FILENAME = "variations_seed_pref";
+
+    // Synchronization lock to prevent simultaneous local seed file writing
+    private static final Object sLock = new Object();
+
+    private AwVariationsSeedFetcher() {}
+
+    /**
+     * Store the variations seed preference.
+     */
+    public static class SeedPreference {
+        public boolean isGzipCompressed;
+        public long lastFetchTime;
+        public String signature;
+        public String country;
+        public String date;
+
+        public SeedPreference(VariationsSeedFetcher.SeedInfo info) {
+            isGzipCompressed = info.isGzipCompressed;
+            signature = info.signature;
+            country = info.country;
+            date = info.date;
+        }
+    }
+
+    public static void fetchSeed(String restrictMode) {
+        assert !ThreadUtils.runningOnUiThread();
+        // Prevent multiple simultaneous file writing
+        synchronized (sLock) {
+            try {
+                VariationsSeedFetcher.SeedInfo si = VariationsSeedFetcher.get().downloadContent(
+                        VariationsSeedFetcher.VariationsPlatform.ANDROID_WEBVIEW, restrictMode);
+                if (si != null) {
+                    SeedPreference sp = new SeedPreference(si);
+                    sp.lastFetchTime = SystemClock.elapsedRealtime();
+                    storeSeed(si.rawSeed, sp);
+                }
+            } catch (SocketTimeoutException e) {
+            } catch (UnknownHostException e) {
+            } catch (IOException e) {
+            }
+        }
+    }
+
+    private static void storeSeed(final byte[] rawSeed, final SeedPreference sp) {
+        FileOutputStream fosSeed = null;
+        ObjectOutputStream oosSeedPref = null;
+        final Context appContext = ContextUtils.getApplicationContext();
+        try {
+            fosSeed = appContext.openFileOutput(SEED_DATA_FILENAME, Context.MODE_PRIVATE);
+            fosSeed.write(rawSeed, 0, rawSeed.length);
+            oosSeedPref = new ObjectOutputStream(
+                    appContext.openFileOutput(SEED_DATA_PREF_FILENAME, Context.MODE_PRIVATE));
+            oosSeedPref.writeObject(sp);
+        } catch (FileNotFoundException e) {
+            Log.e(TAG, "FileNotFoundException store seed.");
+        } catch (IOException e) {
+            Log.e(TAG, "IOException store seed");
+        } finally {
+            if (fosSeed != null) {
+                try {
+                    fosSeed.close();
+                } catch (IOException e) {
+                    Log.e(TAG, "IOException file close");
+                }
+            }
+            if (oosSeedPref != null) {
+                try {
+                    oosSeedPref.close();
+                } catch (IOException e) {
+                    Log.e(TAG, "IOException file close");
+                }
+            }
+        }
+    }
+}