Adds link disambiguation popup support to Windows.

chrome/browser/ui/views/link_disambiguation/link_disambiguation_popup.h

+// Copyright (c) 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 CHROME_BROWSER_UI_VIEWS_LINK_DISAMBIGUATION_LINK_DISAMBIGUATION_POPUP_H_
+#define CHROME_BROWSER_UI_VIEWS_LINK_DISAMBIGUATION_LINK_DISAMBIGUATION_POPUP_H_
+
+#include "base/callback_forward.h"
+#include "content/public/browser/web_contents_view_delegate.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/image/image.h"
+
+namespace aura {
+class Window;
+}
+
+// Creates a popup with a zoomed bitmap rendered by Blink of an area in web
+// |content| that received an ambiguous Gesture event. This allows the user to
+// select which of the links their first Gesture event overlapped. The popup
+// generates a new Gesture event which is sent back to the provided |callback|.
+class LinkDisambiguationPopup {
+ public:
+  explicit LinkDisambiguationPopup();

[sky, 2014/07/30 21:50:36]

nit: no explicit

[luken, 2014/07/31 01:41:47]

Done.

+  ~LinkDisambiguationPopup();
+
+  // Creates and shows the Popup. |zoomed_bitmap| is the scaled-up image of the
+  // ambiguous web content. |target_rect| is the original, unzoomed rectangle
+  // in DIPs in the coordinate system of |content|. We will convert received
+  // gestures in the popup to the coordinate system of |content| and as an
+  // offset within |target_rect|, and then call the |callback| with the
+  // transformed coordinates GestureEvent.
+  void Show(const SkBitmap& zoomed_bitmap,
+            const gfx::Rect& target_rect,

[sky, 2014/07/30 21:50:37]

Might target_rect change while the popup is up? What if the page scrolls?

[luken, 2014/07/31 01:41:47]

You are correct, good catch, |target_rect| does change when the page scrolls.
However if the page scrolls I think the popup should just close, similar to how
Context Menus work. This is also how the gesture scrolling works, in that if the
user touches the underlying page in order to scroll it the popup is dismissed.

[sky, 2014/07/31 15:37:40]

Certainly the popup will close if the users touches on the page, but what if the
page scrolls itself?

+            const gfx::NativeView content,
+            content::WebContentsViewDelegate::GestureCallback callback);

[sky, 2014/07/30 21:50:37]

const &?

[luken, 2014/07/31 01:41:47]

Done.

+  void Close();
+
+ private:
+  class ZoomBubbleView;
+
+  // It is possible that |view_| can be destroyed by its widget instead of
+  // closed explicitly by us. In that case we need to be notified that it has
+  // been destroyed so we can invalidate our own pointer to that view.
+  void InvalidateBubbleView();
+
+  const aura::Window* content_;
+  ZoomBubbleView* view_;
+  gfx::Image zoomed_image_;
+};

[sky, 2014/07/30 21:50:36]

DISALLOW_...

[luken, 2014/07/31 01:41:47]

Done.

+
+#endif  // CHROME_BROWSER_UI_VIEWS_LINK_DISAMBIGUATION_LINK_DISAMBIGUATION_POPUP_H_