Re-land r93365 - add RefCountedString

chrome/browser/printing/print_preview_message_handler.cc

 // Copyright (c) 2011 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 "chrome/browser/printing/print_preview_message_handler.h"
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 123 matching lines @@
   base::SharedMemory* shared_buf =
       new base::SharedMemory(params.metafile_data_handle, true);
   if (!shared_buf->Map(params.data_size)) {
     NOTREACHED();
     delete shared_buf;
     return;
   }
 
   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(
       params.expected_pages_count,
       wrapper->print_view_manager()->RenderSourceName(),
       params.modifiable,
       params.preview_request_id);
 }
 
 void PrintPreviewMessageHandler::OnPrintPreviewFailed(int document_cookie) {
@@ skipping 40 matching lines @@
 }
 
 void PrintPreviewMessageHandler::DidStartLoading() {
   if (tab_contents()->delegate() &&
       printing::PrintPreviewTabController::IsPrintPreviewTab(tab_contents())) {
     tab_contents()->SetContentRestrictions(CONTENT_RESTRICTION_PRINT);
   }
 }
 
 }  // namespace printing