Re-land r93365 - add RefCountedString

chrome/browser/printing/print_preview_message_handler.cc

Index: chrome/browser/printing/print_preview_message_handler.cc
diff --git a/chrome/browser/printing/print_preview_message_handler.cc b/chrome/browser/printing/print_preview_message_handler.cc
index 99be3f5e6257255683cb89165809b25d0a072aa6..75aa54c11e7975cf9c52d8d1aa87360201e0774b 100644
--- a/chrome/browser/printing/print_preview_message_handler.cc
+++ b/chrome/browser/printing/print_preview_message_handler.cc
@@ -141,14 +141,15 @@ void PrintPreviewMessageHandler::OnPagesReadyForPreview(
 
   wrapper->print_view_manager()->OverrideTitle(tab_contents());
 
-  char* preview_data = static_cast<char*>(shared_buf->memory());
+  const unsigned char* preview_data =
+      static_cast<unsigned char*>(shared_buf->memory());
   uint32 preview_data_size = params.data_size;
 
+  // TODO(joth): This seems like a good match for using RefCountedStaticMemory
+  // to avoid the memory copy, but the SetPrintPreviewData call chain below
+  // needs updating to accept the RefCountedMemory* base class.
   scoped_refptr<RefCountedBytes> html_bytes(new RefCountedBytes);
-  html_bytes->data.resize(preview_data_size);
-  std::vector<unsigned char>::iterator it = html_bytes->data.begin();
-  for (uint32 i = 0; i < preview_data_size; ++i, ++it)
-    *it = *(preview_data + i);
+  html_bytes->data().assign(preview_data, preview_data + preview_data_size);
 
   print_preview_ui->SetPrintPreviewData(html_bytes.get());
   print_preview_ui->OnPreviewDataIsAvailable(