Add Browser Actions tab model selector and open a tab through it if ChromeTabbedActivity is not ava…

chrome/android/java/src/org/chromium/chrome/browser/browseractions/BrowserActionsTabPersistencePolicy.java

+// 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.chrome.browser.browseractions;
+
+import android.os.StrictMode;
+
+import org.chromium.base.Callback;
+import org.chromium.base.Log;
+import org.chromium.chrome.browser.compositor.layouts.content.TabContentManager;
+import org.chromium.chrome.browser.tabmodel.TabPersistencePolicy;
+import org.chromium.chrome.browser.tabmodel.TabPersistentStore;
+
+import java.io.File;
+import java.util.List;
+import java.util.concurrent.Executor;
+
+import javax.annotation.Nullable;
+
+/**
+ * Handles the Browser Actions Tab specific behaviors of tab persistence.
+ */
+public class BrowserActionsTabPersistencePolicy implements TabPersistencePolicy {
+    static final String SAVED_STATE_DIRECTORY = "browser_actions";
+
+    private static final String TAG = "tabmodel";
+
+    /** Prevents two state directories from getting created simultaneously. */
+    private static final Object DIR_CREATION_LOCK = new Object();
+
+    private static File sStateDirectory;
+
+    @Override
+    public File getOrCreateStateDirectory() {

[Yusuf, 2017/07/18 22:59:47]

so the only current behavior change from the parent is the directory. What next
to add here?

[ltian, 2017/08/07 23:24:11]

To merge the Browser Actions tabs into normal Chrome tab model, we might have
somthing similar to detachAndStartReparenting() which binds the tab with
ChromeActivity and TabContentMananger. This files will have changes about clean
up the merged files. 

+        return getOrCreateBrowserActionsModeStateDirectory();
+    }
+
+    @Override
+    public String getStateFileName() {
+        return TabPersistentStore.getStateFileName("0");
+    }
+
+    @Override
+    public boolean shouldMergeOnStartup() {

[Yusuf, 2017/07/18 22:59:47]

so we are not merging the tabs back in yet? What happens to the tabs in the
tabmodelselector when user opens back Chrome?

[ltian, 2017/08/07 23:24:11]

Yes, this CL does not deal with tab merging. So if user opens the Chrome, newly
added tabs will not be added to the Chrome tab model. 

+        return false;
+    }
+
+    @Override
+    @Nullable
+    public String getStateToBeMergedFileName() {
+        return null;
+    }
+
+    @Override
+    public boolean performInitialization(Executor executor) {
+        return true;
+    }
+
+    @Override
+    public void waitForInitializationToFinish() {}
+
+    @Override
+    public boolean isMergeInProgress() {
+        return false;
+    }
+
+    @Override
+    public void setMergeInProgress(boolean isStarted) {
+        assert false : "Merge not supported in Browser Actions";
+    }
+
+    @Override
+    public void cancelCleanupInProgress() {}
+
+    @Override
+    public void cleanupUnusedFiles(Callback<List<String>> filesToDelete) {}
+
+    @Override
+    public void setTabContentManager(TabContentManager cache) {}
+
+    @Override
+    public void notifyStateLoaded(int tabCountAtStartup) {}
+
+    @Override
+    public void destroy() {}
+
+    /**
+     * The folder where the state should be saved to.
+     * @return A file representing the directory that contains TabModelSelector states.
+     */
+    public static File getOrCreateBrowserActionsModeStateDirectory() {
+        synchronized (DIR_CREATION_LOCK) {
+            if (sStateDirectory == null) {
+                sStateDirectory = new File(
+                        TabPersistentStore.getOrCreateBaseStateDirectory(), SAVED_STATE_DIRECTORY);
+                StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
+                try {
+                    if (!sStateDirectory.exists() && !sStateDirectory.mkdirs()) {
+                        Log.e(TAG, "Failed to create state folder: " + sStateDirectory);
+                    }
+                } finally {
+                    StrictMode.setThreadPolicy(oldPolicy);
+                }
+            }
+        }
+        return sStateDirectory;
+    }
+}