Fetch Finch seed during restore

chrome/android/java/src/org/chromium/chrome/browser/ChromeBackupAgent.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeBackupAgent.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeBackupAgent.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeBackupAgent.java
index 299863812d7f3dead9934f5f51bc86788a2f988e..6e400876ab6b4c6d49b82dce9a742e47fae24a6a 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeBackupAgent.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeBackupAgent.java
@@ -13,6 +13,7 @@ import android.os.ParcelFileDescriptor;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
+import org.chromium.base.PathUtils;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.SuppressFBWarnings;
@@ -20,6 +21,7 @@ import org.chromium.base.library_loader.ProcessInitException;
 import org.chromium.chrome.browser.firstrun.FirstRunGlueImpl;
 import org.chromium.chrome.browser.firstrun.FirstRunSignInProcessor;
 import org.chromium.chrome.browser.firstrun.FirstRunStatus;
+import org.chromium.chrome.browser.init.AsyncInitTaskRunner;
 import org.chromium.chrome.browser.init.ChromeBrowserInitializer;
 import org.chromium.chrome.browser.preferences.privacy.PrivacyPreferencesManager;
 import org.chromium.components.signin.AccountManagerHelper;
@@ -33,6 +35,8 @@ import java.io.ObjectOutputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.concurrent.Callable;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Backup agent for Chrome, using Android key/value backup.
@@ -54,6 +58,10 @@ public class ChromeBackupAgent extends BackupAgent {
             PrivacyPreferencesManager.PREF_METRICS_REPORTING,
     };
 
+    // Timeout for running the background tasks, needs to be quite long since they may be doing
+    // network access, but must be less than the 1 minute restore timeout to be useful.
+    private static final long BACKGROUND_TASK_TIMEOUT_SECS = 20;
+
     /**
      * Class to save and restore the backup state, used to decide if backups are needed. Since the
      * backup data is small, and stored as private data by the backup service, this can simply store
@@ -111,7 +119,7 @@ public class ChromeBackupAgent extends BackupAgent {
         try {
             ChromeBrowserInitializer.getInstance(context).handleSynchronousStartup();
         } catch (ProcessInitException e) {
-            Log.w(TAG, "Browser launch failed on restore: " + e);
+            Log.w(TAG, "Browser launch failed on backup or restore: " + e);
             return false;
         }
         return true;
@@ -134,27 +142,29 @@ public class ChromeBackupAgent extends BackupAgent {
         final ArrayList<byte[]> backupValues = new ArrayList<>();
 
         // The native preferences can only be read on the UI thread.
-        if (!ThreadUtils.runOnUiThreadBlockingNoException(new Callable<Boolean>() {
-                @Override
-                public Boolean call() {
-                    // Start the browser if necessary, so that Chrome can access the native
-                    // preferences. Although Chrome requests the backup, it doesn't happen
-                    // immediately, so by the time it does Chrome may not be running.
-                    if (!initializeBrowser(backupAgent)) return false;
-
-                    String[] nativeBackupNames = nativeGetBoolBackupNames();
-                    boolean[] nativeBackupValues = nativeGetBoolBackupValues();
-                    assert nativeBackupNames.length == nativeBackupValues.length;
-
-                    for (String name : nativeBackupNames) {
-                        backupNames.add(NATIVE_PREF_PREFIX + name);
-                    }
-                    for (boolean val : nativeBackupValues) {
-                        backupValues.add(booleanToBytes(val));
+        Boolean nativePrefsRead =
+                ThreadUtils.runOnUiThreadBlockingNoException(new Callable<Boolean>() {
+                    @Override
+                    public Boolean call() {
+                        // Start the browser if necessary, so that Chrome can access the native
+                        // preferences. Although Chrome requests the backup, it doesn't happen
+                        // immediately, so by the time it does Chrome may not be running.
+                        if (!initializeBrowser(backupAgent)) return false;
+
+                        String[] nativeBackupNames = nativeGetBoolBackupNames();
+                        boolean[] nativeBackupValues = nativeGetBoolBackupValues();
+                        assert nativeBackupNames.length == nativeBackupValues.length;
+
+                        for (String name : nativeBackupNames) {
+                            backupNames.add(NATIVE_PREF_PREFIX + name);
+                        }
+                        for (boolean val : nativeBackupValues) {
+                            backupValues.add(booleanToBytes(val));
+                        }
+                        return true;
                     }
-                    return true;
-                }
-            })) {
+                });
+        if (!nativePrefsRead) {
             // Something went wrong reading the native preferences, skip the backup.
             return;
         }
@@ -201,6 +211,9 @@ public class ChromeBackupAgent extends BackupAgent {
     @Override
     public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState)
             throws IOException {
+        // TODO(aberent) Check that this is not running on the UI thread. Doing so, however, makes
+        // testing difficult since the test code runs on the UI thread.
+
         // Check that the user hasn't already seen FRE (not sure if this can ever happen, but if it
         // does then restoring the backup will overwrite the user's choices).
         SharedPreferences sharedPrefs = ContextUtils.getAppSharedPreferences();
@@ -227,16 +240,45 @@ public class ChromeBackupAgent extends BackupAgent {
                 backupValues.add(buffer);
             }
         }
+        // Start and wait for the Async init tasks. This loads the library, and attempts to load the
+        // first run variations seed. Since these are both slow it makes sense to run them in
+        // parallel as Android AsyncTasks, reusing some of Chrome's async startup logic.
+        //
+        // Note that this depends on onRestore being run from a background thread, since
+        // if it were called from the UI thread the broadcast would not be received until after it
+        // exited.
+        final CountDownLatch latch = new CountDownLatch(1);
+        ThreadUtils.runOnUiThreadBlocking(new Runnable() {
+            @Override
+            public void run() {
+                // Chrome library loading depends on PathUtils.
+                PathUtils.setPrivateDataDirectorySuffix(
+                        ChromeBrowserInitializer.PRIVATE_DATA_DIRECTORY_SUFFIX);
+                createAsyncInitTaskRunner(latch).startBackgroundTasks(
+                        false /* allocateChildConnection */, true /* initVariationSeed */);
+            }
+        });
 
-        // Chrome has to be running before it can check if the account exists.
+        try {
+            // Ignore result. It will only be false if it times out. Problems with fetching the
+            // variation seed can be ignored, and other problems will either recover or be repeated
+            // when Chrome is started synchronously.
+            latch.await(BACKGROUND_TASK_TIMEOUT_SECS, TimeUnit.SECONDS);
+        } catch (InterruptedException e) {
+            // Should never happen, but can be ignored (as explained above) anyway.
+        }
+        // Chrome has to be running before it can check if the account exists. Because the native
+        // library is already loaded Chrome startup should be fast.
         final ChromeBackupAgent backupAgent = this;
-        if (!ThreadUtils.runOnUiThreadBlockingNoException(new Callable<Boolean>() {
-                @Override
-                public Boolean call() {
-                    // Start the browser if necessary.
-                    return initializeBrowser(backupAgent);
-                }
-            })) {
+        boolean browserStarted =
+                ThreadUtils.runOnUiThreadBlockingNoException(new Callable<Boolean>() {
+                    @Override
+                    public Boolean call() {
+                        // Start the browser if necessary.
+                        return initializeBrowser(backupAgent);
+                    }
+                });
+        if (!browserStarted) {
             // Something went wrong starting Chrome, skip the restore.
             return;
         }
@@ -293,6 +335,24 @@ public class ChromeBackupAgent extends BackupAgent {
     }
 
     @VisibleForTesting
+    AsyncInitTaskRunner createAsyncInitTaskRunner(final CountDownLatch latch) {
+        return new AsyncInitTaskRunner() {
+
+            @Override
+            protected void onSuccess() {
+                latch.countDown();
+            }
+
+            @Override
+            protected void onFailure() {
+                // Ignore failure. Problems with the variation seed can be ignored, and other
+                // problems will either recover or be repeated when Chrome is started synchronously.
+                latch.countDown();
+            }
+        };
+    }
+
+    @VisibleForTesting
     protected native String[] nativeGetBoolBackupNames();
 
     @VisibleForTesting