Add support for figure element

java/org/chromium/distiller/webdocument/WebFigure.java

+package org.chromium.distiller.webdocument;
+
+import com.google.gwt.dom.client.Document;
+import com.google.gwt.dom.client.Element;
+import org.chromium.distiller.DomUtil;
+
+/**
+ * WebFigure represents a html figure tag which contains an image and

[wychen, 2016/08/05 02:13:03]

... represents a figure element, containing an image and optionally a caption.

+ * may or may not contain a caption.
+ */
+public class WebFigure extends WebImage {
+
+    private Element figCaption;
+
+    /**
+     * Build a figure element.
+     * @param e The element detected as an image.
+     * @param w The original width of the image.
+     * @param h The original height of the image.
+     * @param src The source URL of the image being extracted.
+     * @param caption The element containing the caption of the image.
+     */
+    public WebFigure(Element e, int w, int h, String src, Element caption) {
+        super(e, w, h, src);
+        figCaption = caption;
+    }
+
+    @Override
+    /**
+     * WebFigure extends WebImage so it can use WebImage generated output
+     * and just handle he caption since an html figure is basically a

[wychen, 2016/08/05 02:13:03]

the

+     * placeholder for an image and a caption.
+     */
+    public String generateOutput(boolean textOnly) {
+        String caption = DomUtil.generateOutputFromTree(figCaption, textOnly);
+        if (textOnly) return caption;
+
+        Element figure = Document.get().createElement("FIGURE");
+        figure.setInnerHTML(super.generateOutput(false));

[wychen, 2016/08/05 02:13:03]

Could you rebase and add to WebImage:
protected ImageElement getProcessedNode()

Then use that element here, instead of calling setInnerHTML?

+        if (!figCaption.getInnerHTML().isEmpty()) {
+            Element container = Document.get().createElement("DIV");

[wychen, 2016/08/05 02:13:03]

We could just use:
figure.appendChild(caption)

+            container.setInnerHTML(caption);
+            figure.appendChild(container.getChild(0));
+        }
+        return figure.getString();
+    }
+}