gpu: Refactor GpuMemoryBuffer framework for multi-process support.

ui/gl/gl_image_shm.cc

 // Copyright 2013 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.
 
 #include "ui/gl/gl_image_shm.h"
 
 #include "base/debug/trace_event.h"
 #include "base/process/process_handle.h"
 #include "ui/gl/gl_bindings.h"
 
 namespace gfx {
 
-GLImageShm::GLImageShm(gfx::Size size) : size_(size) {
+GLImageShm::GLImageShm(gfx::Size size, unsigned internalformat)
+    : size_(size),
+      internalformat_(internalformat) {
+  // GL_RGBA8_OES is currently the only supported internalformat.
+  DCHECK_EQ(static_cast<GLenum>(GL_RGBA8_OES), internalformat);
 }
 
 GLImageShm::~GLImageShm() {
   Destroy();
 }
 
 bool GLImageShm::Initialize(gfx::GpuMemoryBufferHandle buffer) {
   if (!base::SharedMemory::IsHandleValid(buffer.handle))
     return false;
 
   base::SharedMemory shared_memory(buffer.handle, true);
 
   // Duplicate the handle.
   base::SharedMemoryHandle duped_shared_memory_handle;
   if (!shared_memory.ShareToProcess(base::GetCurrentProcessHandle(),
                                     &duped_shared_memory_handle)) {
     DVLOG(0) << "Failed to duplicate shared memory handle.";
     return false;
   }
 
   shared_memory_.reset(
       new base::SharedMemory(duped_shared_memory_handle, true));
   return true;
 }
 
 bool GLImageShm::BindTexImage() {
   TRACE_EVENT0("gpu", "GLImageShm::BindTexImage");
   DCHECK(shared_memory_);
 
-  const int kBytesPerPixel = 4;
-  size_t size = size_.GetArea() * kBytesPerPixel;
+  GLenum internalformat;
+  GLenum format;
+  GLenum type;
+  int bytes_per_pixel;
+  switch (internalformat_) {
+    case GL_RGBA8_OES:
+      internalformat = GL_RGBA;
+      format = GL_RGBA;
+      type = GL_UNSIGNED_BYTE;
+      bytes_per_pixel = 4;
+      break;
+    default:
+      DVLOG(0) << "Invalid format: " << internalformat_;
+      return false;
+  }
+
+  size_t size = size_.GetArea() * bytes_per_pixel;
   DCHECK(!shared_memory_->memory());
   if (!shared_memory_->Map(size)) {
     DVLOG(0) << "Failed to map shared memory.";
     return false;
   }
 
   DCHECK(shared_memory_->memory());
   glTexImage2D(GL_TEXTURE_2D,
                0,  // mip level
-               GL_RGBA,
+               internalformat,
                size_.width(),
                size_.height(),
                0,  // border
-               GL_RGBA,
-               GL_UNSIGNED_BYTE,
+               format,
+               type,
                shared_memory_->memory());
 
   shared_memory_->Unmap();
   return true;
 }
 
 gfx::Size GLImageShm::GetSize() {
   return size_;
 }
 
 void GLImageShm::Destroy() {
 }
 
 void GLImageShm::ReleaseTexImage() {
 }
 
 }  // namespace gfx