Create entry to PWSharing through ShareHelper

chrome/android/java/src/org/chromium/chrome/browser/share/ShareActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/share/ShareActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/share/ShareActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/share/ShareActivity.java
new file mode 100644
index 0000000000000000000000000000000000000000..aabb6e6d465617a4f5c723dd595caf31a22a08d1
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/share/ShareActivity.java
@@ -0,0 +1,77 @@
+// 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.share;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.util.IntentUtils;
+
+import java.lang.ref.WeakReference;
+import java.util.List;
+
+/**
+ * {@code ShareActivity} is the base class for share options, which
+ * are activities that are shown in the share chooser. Activities subclassing
+ * ShareActivity override featureIsEnabled, and handleShareAction.
+ */
+public abstract class ShareActivity extends AppCompatActivity {
+
+    @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;
+            if (!IntentUtils.safeHasExtra(intent, ShareHelper.EXTRA_TASK_ID)) return;
+            handleShareAction();
+        } finally {
+            finish();
+        }
+    }
+
+    /**
+     * Returns the ChromeActivity that called the share intent picker.
+     */
+    protected ChromeActivity getTriggeringActivity() {
+        int triggeringTaskId =
+                IntentUtils.safeGetIntExtra(getIntent(), ShareHelper.EXTRA_TASK_ID, 0);
+        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() == triggeringTaskId
+                    && activity instanceof ChromeActivity) {
+                return (ChromeActivity) activity;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Override to handle the desired action of the activity.
+     */
+    protected abstract void handleShareAction();
+
+    /**
+     * Override this method to describe the conditions this share option should be present
+     * in the share chooser.
+     * @param currentTab    The current Tab that chrome has open. This gives access to
+     *                      critical information such as MIME type or Nativity.
+     * @return {@code true} if feature should be enabled.
+     */
+    public abstract boolean featureIsEnabled(Tab currentTab);
+}