Avoid OOB memcpy in chrome_pdf::CopyImage.

ppapi/cpp/image_data.cc

 // Copyright (c) 2012 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 "ppapi/cpp/image_data.h"
 
 #include <string.h>  // Needed for memset.
 
 #include <algorithm>
 
@@ skipping 56 matching lines @@
   return const_cast<ImageData*>(this)->GetAddr32(coord);
 }
 
 uint32_t* ImageData::GetAddr32(const Point& coord) {
   // If we add more image format types that aren't 32-bit, we'd want to check
   // here and fail.
   return reinterpret_cast<uint32_t*>(
       &static_cast<char*>(data())[coord.y() * stride() + coord.x() * 4]);
 }
 
+bool ImageData::Contains(const pp::Rect& rect) const {
+  return rect.width() >= 0 && rect.height() >= 0 &&
+      pp::Rect(size()).Contains(rect);
+}
+
 // static
 bool ImageData::IsImageDataFormatSupported(PP_ImageDataFormat format) {
   if (!has_interface<PPB_ImageData_1_0>())
     return false;
   return PP_ToBool(get_interface<PPB_ImageData_1_0>()->
       IsImageDataFormatSupported(format));
 }
 
 // static
 PP_ImageDataFormat ImageData::GetNativeImageDataFormat() {
   if (!has_interface<PPB_ImageData_1_0>())
     return PP_IMAGEDATAFORMAT_BGRA_PREMUL;  // Default to something on failure.
   return get_interface<PPB_ImageData_1_0>()->GetNativeImageDataFormat();
 }
 
 void ImageData::InitData() {
   if (!has_interface<PPB_ImageData_1_0>())
     return;
   if (get_interface<PPB_ImageData_1_0>()->Describe(pp_resource(), &desc_)) {
     data_ = get_interface<PPB_ImageData_1_0>()->Map(pp_resource());
     if (data_)
       return;
   }
   *this = ImageData();
 }
 
 }  // namespace pp