Add support for multipage distillation.

components/dom_distiller/core/page_distiller.h

+// Copyright 2014 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.
+
+#ifndef COMPONENTS_DOM_DISTILLER_CORE_PAGE_DISTILLER_H_
+#define COMPONENTS_DOM_DISTILLER_CORE_PAGE_DISTILLER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/values.h"
+#include "components/dom_distiller/core/distiller_page.h"
+#include "url/gurl.h"
+
+namespace dom_distiller {
+
+class DistillerImpl;
+
+struct DistilledPageInfo {
+  std::string title;
+  std::string html;
+  std::string next_page_url;
+  std::vector<std::string> image_urls;
+  DistilledPageInfo();
+  ~DistilledPageInfo();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DistilledPageInfo);
+};
+
+// Distills a single page of an article.
+class PageDistiller : public DistillerPage::Delegate {
+ public:
+  typedef base::Callback<void(scoped_ptr<DistilledPageInfo> distilled_page,
+                              bool distillation_successful)>
+      PageDistillerCallback;
+  explicit PageDistiller(const DistillerPageFactory& distiller_page_factory);
+  virtual ~PageDistiller();
+
+  // Creates an execution context. This must be called once before any calls are
+  // made to distill the page.
+  virtual void Init();
+
+  // Distills the |url| and posts the |callback| with results.
+  virtual void DistillPage(const GURL& url,
+                           const PageDistillerCallback& callback);
+
+  // DistillerPage::Delegate
+  virtual void OnLoadURLDone() OVERRIDE;
+  virtual void OnExecuteJavaScriptDone(const GURL& page_url,
+                                       const base::Value* value) OVERRIDE;
+
+ private:
+  virtual void LoadURL(const GURL& url);
+
+  // Injects JavaScript to distill a loaded page down to its important content,
+  // e.g., extracting a news article from its surrounding boilerplate.
+  void GetDistilledContent();
+
+  scoped_ptr<DistillerPage> distiller_page_;
+  PageDistillerCallback page_distiller_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(PageDistiller);
+};
+
+}  // namespace dom_distiller
+
+#endif  // COMPONENTS_DOM_DISTILLER_CORE_PAGE_DISTILLER_H_