Add support for compressed GPU memory buffers.

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"
 
 #if defined(OS_WIN) || defined(USE_X11) || defined(OS_ANDROID) || \
     defined(USE_OZONE)
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
 #endif
 
 #include "base/numerics/safe_math.h"
 #include "ui/gfx/gpu_memory_buffer.h"
 
 namespace gfx {
 
 class GL_EXPORT GLImageMemory : public GLImage {
  public:
   GLImageMemory(const gfx::Size& size, unsigned internalformat);
 
   static bool StrideInBytes(size_t width,
                             gfx::GpuMemoryBuffer::Format format,
                             size_t* stride_in_bytes);
 
+  static bool ValidSize(const gfx::Size& size,
+                        gfx::GpuMemoryBuffer::Format format);
+
   bool Initialize(const unsigned char* memory,
                   gfx::GpuMemoryBuffer::Format format);
 
   // Overridden from GLImage:
   void Destroy(bool have_context) override;
   gfx::Size GetSize() override;
   bool BindTexImage(unsigned target) override;
   void ReleaseTexImage(unsigned target) override {}
   bool CopyTexImage(unsigned target) override;
   void WillUseTexImage() override;
@@ skipping 24 matching lines @@
   unsigned egl_texture_id_;
   EGLImageKHR egl_image_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(GLImageMemory);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_IMAGE_MEMORY_H_