Support <picture> in image extraction

javatests/org/chromium/distiller/webdocument/WebImageTest.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.distiller.webdocument;
 
 import org.chromium.distiller.DomDistillerJsTestCase;
 
 import java.util.List;
 
 import com.google.gwt.dom.client.Document;
+import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.ImageElement;
+import org.chromium.distiller.DomUtil;
 
 public class WebImageTest extends DomDistillerJsTestCase {
     public void testGetSrcList() {
+        mHead.setInnerHTML("<base href=\"http://example.com/\">");
+
         ImageElement img = Document.get().createImageElement();
-        img.setSrc("http://example.com/image");
+        img.setSrc("image");
         img.setAttribute("srcset",
-                "http://example.com/image200 200w, http://example.com/image400 400w");
+                "image200 200w, image400 400w");
         WebImage wi = new WebImage(img, 1, 1, img.getSrc());
         List<String> urls = wi.getUrlList();
         assertEquals(3, urls.size());
         assertEquals("http://example.com/image", urls.get(0));
         assertEquals("http://example.com/image200", urls.get(1));
         assertEquals("http://example.com/image400", urls.get(2));
     }
+
+    public void testGetSrcListInPicture() {
+        mHead.setInnerHTML("<base href=\"http://example.com/\">");
+
+        String html =
+            "<picture>" +
+              "<source data-srcset=\"image200 200w, //example.org/image400 400w\">" +
+              "<source srcset=\"image100 100w, //example.org/image300 300w\">" +
+              "<img>" +
+            "</picture>";
+        Element container = Document.get().createDivElement();
+        container.setInnerHTML(html);
+        WebImage wi = new WebImage(container.getFirstChildElement(), 1, 1, "");
+        List<String> urls = wi.getUrlList();
+        assertEquals(4, urls.size());
+        assertEquals("http://example.com/image200", urls.get(0));
+        assertEquals("http://example.org/image400", urls.get(1));
+        assertEquals("http://example.com/image100", urls.get(2));
+        assertEquals("http://example.org/image300", urls.get(3));
+    }
+
+    public void testGenerateOutput() {
+        mHead.setInnerHTML("<base href=\"http://example.com/\">");
+
+        String html =
+                "<picture>" +
+                  "<source srcset=\"image\">" +
+                  "<img dirty-attributes>" +
+                "</picture>";
+        Element container = Document.get().createDivElement();
+        container.setInnerHTML(html);
+        WebImage wi = new WebImage(container.getFirstChildElement(), 0, 0, "");
+        assertEquals("<picture><source srcset=\"http://example.com/image\"><img></picture>",
+                wi.generateOutput(false));
+    }
 }