Remove the print option from the menu and make it a share destination.

chrome/android/java/src/org/chromium/chrome/browser/printing/PrintShareActivity.java

+// 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.printing;
+
+import android.app.Activity;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+
+import org.chromium.base.ActivityState;
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ApplicationStatus.ActivityStateListener;
+import org.chromium.base.ContextUtils;
+import org.chromium.base.ThreadUtils;
+import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ChromeActivity;
+
+import java.lang.ref.WeakReference;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * A simple activity that allows Chrome to expose print as an option in the share menu.
+ */
+public class PrintShareActivity extends AppCompatActivity {
+
+    private static Set<Activity> sPendingShareActivities = new HashSet<>();
+    private static ActivityStateListener sStateListener;
+
+    /**
+     * Enable the print sharing option.
+     *
+     * @param activity The activity that will be triggering the share action.  The activitiy's
+     *                 state will be tracked to disable the print option when the share operation
+     *                 has been completed.
+     */
+    public static void enablePrintShareOption(Activity activity) {
+        ThreadUtils.assertOnUiThread();
+
+        if (sStateListener == null) {
+            sStateListener = new ActivityStateListener() {
+                @Override
+                public void onActivityStateChange(Activity activity, int newState) {
+                    if (newState == ActivityState.PAUSED
+                            || newState == ActivityState.RESUMED) {

[Theresa, 2016/07/26 18:23:12]

This should only be ActivityState.PAUSED since the activity will get resumed
when share is dimissed.

+                        return;
+                    }
+                    unregisterActivity(activity);
+                }
+            };
+        }
+        ApplicationStatus.registerStateListenerForAllActivities(sStateListener);
+        boolean wasEmpty = sPendingShareActivities.isEmpty();
+        sPendingShareActivities.add(activity);
+        if (wasEmpty) {
+            activity.getPackageManager().setComponentEnabledSetting(
+                    new ComponentName(activity, PrintShareActivity.class),
+                    PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
+                    PackageManager.DONT_KILL_APP);
+        }
+    }
+
+    private static void unregisterActivity(Activity activity) {
+        sPendingShareActivities.remove(activity);
+        if (!sPendingShareActivities.isEmpty()) return;
+        ApplicationStatus.unregisterActivityStateListener(sStateListener);
+
+        Context context = ContextUtils.getApplicationContext();
+        context.getPackageManager().setComponentEnabledSetting(
+                new ComponentName(context, PrintShareActivity.class),
+                PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
+                PackageManager.DONT_KILL_APP);
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        try {
+            Intent intent = getIntent();
+            if (intent == null) return;
+            if (!Intent.ACTION_SEND.equals(intent.getAction())) return;
+            handlePrintAction();
+        } finally {
+            finish();
+        }
+    }
+
+    private void handlePrintAction() {
+        int currentTaskId = getTaskId();
+        List<WeakReference<Activity>> activities = ApplicationStatus.getRunningActivities();
+        ChromeActivity triggeringActivity = null;
+        for (int i = 0; i < activities.size(); i++) {
+            Activity activity = activities.get(i).get();
+            if (activity == null) continue;
+
+            // Since the share intent is triggered without NEW_TASK or NEW_DOCUMENT, the task ID
+            // of this activity will match that of the triggering activity.
+            if (activity.getTaskId() == currentTaskId
+                    && activity instanceof ChromeActivity) {
+                triggeringActivity = (ChromeActivity) activity;
+                break;
+            }
+        }
+        if (triggeringActivity == null) return;
+        unregisterActivity(triggeringActivity);
+        triggeringActivity.onMenuOrKeyboardAction(R.id.print_id, true);
+    }
+
+}