Reland of Revert of gpu: introduce glCopySubTextureCHROMIUM (patchset #1 id:1 of https://codereview…

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) || \
@@ skipping 19 matching lines @@
                         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;
+  bool CopyTexSubImage(unsigned target, int xoffset, int yoffset) override;
   void WillUseTexImage() override;
   void DidUseTexImage() override;
   void WillModifyTexImage() override {}
   void DidModifyTexImage() override {}
   bool ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                             int z_order,
                             OverlayTransform transform,
                             const Rect& bounds_rect,
                             const RectF& crop_rect) override;
 
@@ skipping 15 matching lines @@
   unsigned egl_texture_id_;
   EGLImageKHR egl_image_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(GLImageMemory);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_IMAGE_MEMORY_H_