Revert "Delete CC."

cc/resources/shared_bitmap.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 "cc/resources/shared_bitmap.h"
+
+#include "base/logging.h"
+#include "base/numerics/safe_math.h"
+#include "base/rand_util.h"
+
+namespace cc {
+
+SharedBitmap::SharedBitmap(uint8* pixels, const SharedBitmapId& id)
+    : pixels_(pixels), id_(id) {
+}
+
+SharedBitmap::~SharedBitmap() {
+}
+
+// static
+bool SharedBitmap::SizeInBytes(const gfx::Size& size, size_t* size_in_bytes) {
+  if (size.IsEmpty())
+    return false;
+  base::CheckedNumeric<size_t> s = 4;
+  s *= size.width();
+  s *= size.height();
+  if (!s.IsValid())
+    return false;
+  *size_in_bytes = s.ValueOrDie();
+  return true;
+}
+
+// static
+size_t SharedBitmap::CheckedSizeInBytes(const gfx::Size& size) {
+  CHECK(!size.IsEmpty());
+  base::CheckedNumeric<size_t> s = 4;
+  s *= size.width();
+  s *= size.height();
+  return s.ValueOrDie();
+}
+
+// static
+size_t SharedBitmap::UncheckedSizeInBytes(const gfx::Size& size) {
+  DCHECK(VerifySizeInBytes(size));
+  size_t s = 4;
+  s *= size.width();
+  s *= size.height();
+  return s;
+}
+
+// static
+bool SharedBitmap::VerifySizeInBytes(const gfx::Size& size) {
+  if (size.IsEmpty())
+    return false;
+  base::CheckedNumeric<size_t> s = 4;
+  s *= size.width();
+  s *= size.height();
+  return s.IsValid();
+}
+
+// static
+SharedBitmapId SharedBitmap::GenerateId() {
+  SharedBitmapId id;
+  // Needs cryptographically-secure random numbers.
+  base::RandBytes(id.name, sizeof(id.name));
+  return id;
+}
+
+}  // namespace cc