Fix race conditions in ImageDecoder.

chrome/utility/chrome_content_utility_client.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 "chrome/utility/chrome_content_utility_client.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/json/json_reader.h"
 #include "base/memory/ref_counted.h"
@@ skipping 189 matching lines @@
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kUtilityProcessEnableMDns)) {
     local_discovery::ServiceDiscoveryMessageHandler::PreSandboxStartup();
   }
 #endif  // ENABLE_MDNS
 }
 
 // static
 SkBitmap ChromeContentUtilityClient::DecodeImage(
     const std::vector<unsigned char>& encoded_data, bool shrink_to_fit) {
-  SkBitmap decoded_image = content::DecodeImage(&encoded_data[0],
-                                                gfx::Size(),
-                                                encoded_data.size());
+  SkBitmap decoded_image;
+  if (encoded_data.empty())
+    return decoded_image;
+
+  decoded_image = content::DecodeImage(&encoded_data[0],
+                                       gfx::Size(),
+                                       encoded_data.size());
 
   int64_t struct_size = sizeof(ChromeUtilityHostMsg_DecodeImage_Succeeded);
   int64_t image_size = decoded_image.computeSize64();
   int halves = 0;
   while (struct_size + (image_size >> 2*halves) > max_ipc_message_size_)
     halves++;
   if (halves) {
     if (shrink_to_fit) {
       // If decoded image is too large for IPC message, shrink it by halves.
       // This prevents quality loss, and should never overshrink on displays
@@ skipping 176 matching lines @@
     const std::string& mime_type, int64 total_size, bool get_attached_images) {
   // Only one IPCDataSource may be created and added to the list of handlers.
   metadata::IPCDataSource* source = new metadata::IPCDataSource(total_size);
   handlers_.push_back(source);
 
   metadata::MediaMetadataParser* parser = new metadata::MediaMetadataParser(
       source, mime_type, get_attached_images);
   parser->Start(base::Bind(&FinishParseMediaMetadata, base::Owned(parser)));
 }
 #endif