[headless] Initial skeleton of headless/public/

headless/public/web_contents.h

+// Copyright 2015 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 HEADLESS_PUBLIC_WEB_CONTENTS_H_
+#define HEADLESS_PUBLIC_WEB_CONTENTS_H_
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "headless/public/headless_export.h"
+#include "url/gurl.h"
+
+class SkBitmap;
+
+namespace content {
+class WebContents;
+}
+
+namespace headless {
+class WebFrame;
+
+// Class representing contents of a browser tab.
+// Should be accessed from browser main thread.
+class HEADLESS_EXPORT WebContents {

[ncarter (slow), 2016/01/20 22:23:20]

I worry that having two "web_contents.h" headers in the codebase will confuse
people encountering snippets of the code (I've opened the wrong one by mistake a
couple of times now, though that's mostly a side effect of how I use my editor).

Any reason not to call this HeadlessContents?

+ public:
+  virtual ~WebContents() {}
+
+  class Observer {
+   public:
+    // Will be called on browser thread.
+    virtual void DocumentOnLoadCompletedInMainFrame() = 0;
+
+    // TODO(altimin): More OnSomething() methods will go here.
+
+   protected:
+    explicit Observer(WebContents* web_contents);
+    virtual ~Observer();
+
+   private:
+    class ObserverImpl;
+    scoped_ptr<ObserverImpl> observer_;
+
+    DISALLOW_COPY_AND_ASSIGN(Observer);
+  };
+
+  // Returns main frame for web page.
+  // Should be called on renderer main thread.
+  virtual WebFrame* MainFrame() = 0;
+
+  // Requests browser tab to nagivate to given url.
+  // Should be called on browser main thread.
+  virtual void OpenURL(const GURL& url) = 0;
+
+  using ScreenshotCallback = base::Callback<void(scoped_ptr<SkBitmap>)>;
+  // Requests an image of web contents.
+  // Should be called on browser main thread.
+  virtual void GetScreenshot(const ScreenshotCallback& callback) = 0;
+
+ protected:
+  virtual content::WebContents* web_contents() = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WebContents);
+};
+
+}  // namespace headless
+
+#endif  // HEADLESS_PUBLIC_WEB_CONTENTS_H_