gpu: Refactor GpuMemoryBuffer framework for multi-process support.

ui/gl/gl_image_shm.cc

+// Copyright (c) 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_util.h"
+#include "ui/gl/gl_bindings.h"
+
+namespace gfx {
+
+GLImageShm::GLImageShm(gfx::Size size) : size_(size) {
+}
+
+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;
+  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_RGBA8_OES,
+               size_.width(),
+               size_.height(),
+               0,  // border
+               GL_BGRA,
+               GL_UNSIGNED_BYTE,
+               shared_memory_->memory());
+
+  shared_memory_->Unmap();
+  return true;
+}
+
+gfx::Size GLImageShm::GetSize() {
+  return size_;
+}
+
+void GLImageShm::Destroy() {
+}
+
+void GLImageShm::ReleaseTexImage() {
+}
+
+}  // namespace gfx