[WebLayer] Delete WebLayer data if it is downgraded.

This CL makes WebLayer delete ALL of its data during startup if it
detects that it was downgraded to a lower major release since the
previous launch. The previous version is maintained in a
SharedPreference.

Bug: 1043217
Change-Id: I12c90d6705be4563a2e3bf07712f96a1136d96c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2052601
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Reviewed-by: Tobias Sargeant <tobiasjs@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749385}

weblayer/browser/android/javatests/BUILD.gn

@@ -13,6 +13,7 @@ android_library("weblayer_java_tests") {
     "src/org/chromium/weblayer/test/CloseTabNewTabCallbackImpl.java",
     "src/org/chromium/weblayer/test/CrashReporterTest.java",
     "src/org/chromium/weblayer/test/DataClearingTest.java",
+    "src/org/chromium/weblayer/test/DowngradeTest.java",
     "src/org/chromium/weblayer/test/DownloadCallbackTest.java",
     "src/org/chromium/weblayer/test/ErrorPageCallbackTest.java",
     "src/org/chromium/weblayer/test/EventUtils.java",

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/DowngradeTest.java

+// Copyright 2020 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.weblayer.test;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import static org.chromium.content_public.browser.test.util.TestThreadUtils.runOnUiThreadBlocking;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.support.test.filters.SmallTest;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.PathUtils;
+import org.chromium.weblayer.shell.InstrumentationActivity;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Tests that WebLayer version changes handle data correctly.
+ */
+@RunWith(WebLayerJUnit4ClassRunner.class)
+public class DowngradeTest {
+    public static final String PREF_LAST_VERSION_CODE =
+            "org.chromium.weblayer.last_version_code_used";
+
+    @Rule
+    public InstrumentationActivityTestRule mActivityTestRule =
+            new InstrumentationActivityTestRule();
+
+    // A test file in the app's data directory. This should never get deleted.
+    private File mAppFile;
+    // A test file in WebLayer's data directory. This should get deleted when we downgrade.
+    private File mWebLayerDataFile;
+
+    @Before
+    public void setUp() throws IOException, PackageManager.NameNotFoundException {
+        PathUtils.setPrivateDataDirectorySuffix("weblayer", "weblayer");
+        mWebLayerDataFile = new File(PathUtils.getDataDirectory(), "testWebLayerFile");
+        assertTrue(mWebLayerDataFile.createNewFile());
+
+        Context context = ContextUtils.getApplicationContext();
+        PackageManager packageManager = context.getPackageManager();
+        PackageInfo packageInfo = packageManager.getPackageInfo(context.getPackageName(), 0);
+        mAppFile = new File(packageInfo.applicationInfo.dataDir, "testAppFile");
+        assertTrue(mAppFile.createNewFile());
+    }
+
+    @After
+    public void tearDown() {
+        mAppFile.delete();
+        mWebLayerDataFile.delete();
+    }
+
+    @Test
+    @SmallTest
+    public void testDowngradeDeletesData() throws IOException {
+        SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
+        prefs.edit().putInt(PREF_LAST_VERSION_CODE, 9999_000_00).apply();
+
+        InstrumentationActivity activity = mActivityTestRule.launchWithProfile("profile");
+        runOnUiThreadBlocking(
+                () -> { activity.loadWebLayerSync(ContextUtils.getApplicationContext()); });
+
+        assertFalse(mWebLayerDataFile.exists());
+        assertTrue(mAppFile.exists());
+    }
+
+    @Test
+    @SmallTest
+    public void testUnknownLastVersionKeepsData() throws IOException {
+        SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
+        assertFalse(prefs.contains(PREF_LAST_VERSION_CODE));
+
+        InstrumentationActivity activity = mActivityTestRule.launchWithProfile("profile");
+        runOnUiThreadBlocking(
+                () -> { activity.loadWebLayerSync(ContextUtils.getApplicationContext()); });
+
+        assertTrue(mWebLayerDataFile.exists());
+        assertTrue(mAppFile.exists());
+    }
+
+    @Test
+    @SmallTest
+    public void testNewVersionKeepsData() {
+        SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
+        prefs.edit().putInt(PREF_LAST_VERSION_CODE, 1_000_00).apply();
+
+        InstrumentationActivity activity = mActivityTestRule.launchWithProfile("profile");
+        runOnUiThreadBlocking(
+                () -> { activity.loadWebLayerSync(ContextUtils.getApplicationContext()); });
+
+        assertTrue(mWebLayerDataFile.exists());
+        assertTrue(mAppFile.exists());
+    }
+}

weblayer/browser/java/org/chromium/weblayer_private/WebLayerImpl.java

@@ -6,6 +6,7 @@ package org.chromium.weblayer_private;
 
 import android.content.Context;
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.res.AssetManager;
@@ -26,6 +27,7 @@ import org.chromium.base.BundleUtils;
 import org.chromium.base.CommandLine;
 import org.chromium.base.ContentUriUtils;
 import org.chromium.base.ContextUtils;
+import org.chromium.base.FileUtils;
 import org.chromium.base.Log;
 import org.chromium.base.PathUtils;
 import org.chromium.base.StrictModeContext;
@@ -78,6 +80,9 @@ public final class WebLayerImpl extends IWebLayer.Stub {
     // signature requirements on the implementation, nor does it use the production code path to
     // load the code. Do not set this in production APKs!
     private static final String PACKAGE_MANIFEST_KEY = "org.chromium.weblayer.WebLayerPackage";
+    // SharedPreferences key storing the versionCode of the most recently loaded WebLayer library.
+    public static final String PREF_LAST_VERSION_CODE =
+            "org.chromium.weblayer.last_version_code_used";
 
     private final ProfileManager mProfileManager = new ProfileManager();
 
@@ -233,11 +238,10 @@ public final class WebLayerImpl extends IWebLayer.Stub {
             }
         }
 
-        // Creating the Android shared preferences object causes I/O. Prewarm during
-        // initialization to avoid this occurring randomly later.
-        // TODO: Do this on a background thread.
+        // Creating the Android shared preferences object causes I/O.
         try (StrictModeContext ignored = StrictModeContext.allowDiskWrites()) {
-            ContextUtils.getAppSharedPreferences();
+            SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
+            deleteDataIfPackageDowngrade(prefs, packageInfo);
         }
 
         DeviceUtils.addDeviceSpecificUserAgentSwitch();
@@ -457,6 +461,49 @@ public final class WebLayerImpl extends IWebLayer.Stub {
         }
     }
 
+    private static void deleteDataIfPackageDowngrade(
+            SharedPreferences prefs, PackageInfo packageInfo) {
+        int previousVersion = prefs.getInt(PREF_LAST_VERSION_CODE, 0);
+        int currentVersion = packageInfo.versionCode;
+        if (getBranchFromVersionCode(currentVersion) < getBranchFromVersionCode(previousVersion)) {
+            // WebLayer was downgraded since the last run. Delete the data and cache directories.
+            File dataDir = new File(PathUtils.getDataDirectory());
+            Log.i(TAG,
+                    "WebLayer package downgraded from " + previousVersion + " to " + currentVersion
+                            + "; deleting contents of " + dataDir);
+            deleteDirectoryContents(dataDir);
+        }
+        if (previousVersion != currentVersion) {
+            prefs.edit().putInt(PREF_LAST_VERSION_CODE, currentVersion).apply();
+        }
+    }
+
+    /**
+     * Chromium versionCodes follow the scheme "BBBBPPPAX":
+     * BBBB: 4 digit branch number. It monotonically increases over time.
+     * PPP:  Patch number in the branch. It is padded with zeroes to the left. These three digits
+     *       may change their meaning in the future.
+     * A:    Architecture digit.
+     * X:    A digit to differentiate APKs for other reasons.
+     *
+     * @return The branch number of versionCode.
+     */
+    private static int getBranchFromVersionCode(int versionCode) {
+        return versionCode / 1_000_00;
+    }
+
+    private static void deleteDirectoryContents(File directory) {
+        File[] files = directory.listFiles();
+        if (files == null) {
+            return;
+        }
+        for (File file : files) {
+            if (!FileUtils.recursivelyDeleteFile(file, FileUtils.DELETE_ALL)) {
+                Log.w(TAG, "Failed to delete " + file);
+            }
+        }
+    }
+
     @NativeMethods
     interface Natives {
         void setRemoteDebuggingEnabled(boolean enabled);

weblayer/shell/android/BUILD.gn

@@ -27,6 +27,7 @@ android_library("weblayer_shell_java") {
 
   deps = [
     ":weblayer_shell_resources",
+    "//base:base_java",
     "//third_party/android_deps:android_support_v4_java",
     "//weblayer/public/java",
   ]

weblayer/shell/android/shell_apk/DEPS

 noparent = True
 include_rules = [
+  "+base/android/java",
   "+weblayer/public/java",
 ]

weblayer/shell/android/shell_apk/src/org/chromium/weblayer/shell/InstrumentationActivity.java

@@ -21,6 +21,7 @@ import android.widget.EditText;
 import android.widget.LinearLayout;
 import android.widget.RelativeLayout;
 
+import org.chromium.base.ContextUtils;
 import org.chromium.weblayer.Browser;
 import org.chromium.weblayer.Profile;
 import org.chromium.weblayer.Tab;
@@ -149,7 +150,8 @@ public class InstrumentationActivity extends FragmentActivity {
 
     private void createWebLayerAsync() {
         try {
-            WebLayer.loadAsync(getApplicationContext(), webLayer -> onWebLayerReady());
+            // Get the Context from ContextUtils so tests get the wrapped version.
+            WebLayer.loadAsync(ContextUtils.getApplicationContext(), webLayer -> onWebLayerReady());
         } catch (UnsupportedVersionException e) {
             throw new RuntimeException("Failed to initialize WebLayer", e);
         }