Include gdk.h in canvas_paint_linux.h, it uses gdk_cairo_create.

skia/ext/canvas_paint_linux.h

 
 // Copyright (c) 2009 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 SKIA_EXT_CANVAS_PAINT_LINUX_H_
 #define SKIA_EXT_CANVAS_PAINT_LINUX_H_
 
 #include "skia/ext/platform_canvas.h"
 
+#include <gdk/gdk.h>
+
 namespace skia {
 
 // A class designed to translate skia painting into a region in a
 // GdkWindow. This class has been adapted from the class with the same name in
 // platform_canvas_win.h. On construction, it will set up a context for
 // painting into, and on destruction, it will commit it to the GdkWindow.
 template <class T>
 class CanvasPaintT : public T {
  public:
   // This constructor assumes the result is opaque.
@@ skipping 69 matching lines @@
   // Disallow copy and assign.
   CanvasPaintT(const CanvasPaintT&);
   CanvasPaintT& operator=(const CanvasPaintT&);
 };
 
 typedef CanvasPaintT<PlatformCanvas> PlatformCanvasPaint;
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_CANVAS_PAINT_LINUX_H_