ui: Add RGBX_8888 buffer format.

ui/gl/gl_image_memory.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 UI_GL_GL_IMAGE_MEMORY_H_
 #define UI_GL_GL_IMAGE_MEMORY_H_
 
 #include "ui/gl/gl_image.h"
 
 #include "base/numerics/safe_math.h"
 #include "ui/gfx/buffer_types.h"
 
 namespace gfx {
 
 class GL_EXPORT GLImageMemory : public GLImage {
  public:
   GLImageMemory(const Size& size, unsigned internalformat);
 
-  static bool StrideInBytes(size_t width,
-                            BufferFormat format,
-                            size_t* stride_in_bytes);
-
   bool Initialize(const unsigned char* memory, BufferFormat format);
 
   // Overridden from GLImage:
   void Destroy(bool have_context) override;
   Size GetSize() override;
   unsigned GetInternalFormat() override;
   bool BindTexImage(unsigned target) override;
   void ReleaseTexImage(unsigned target) override {}
   bool CopyTexImage(unsigned target) override;
   bool CopyTexSubImage(unsigned target,
                        const Point& offset,
                        const Rect& rect) override;
   bool ScheduleOverlayPlane(AcceleratedWidget widget,
                             int z_order,
                             OverlayTransform transform,
                             const Rect& bounds_rect,
                             const RectF& crop_rect) override;
 
+  static unsigned GetInternalFormatForTesting(BufferFormat format);
+
  protected:
   ~GLImageMemory() override;
 
   BufferFormat format() const { return format_; }
 
  private:
   const Size size_;
   const unsigned internalformat_;
   const unsigned char* memory_;
   BufferFormat format_;
 
   DISALLOW_COPY_AND_ASSIGN(GLImageMemory);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_IMAGE_MEMORY_H_