Enable robust decoding of custom wallpaper and allow custom wallpaper on login page

ui/gfx/codec/jpeg_codec.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 "ui/gfx/codec/jpeg_codec.h"
 
 #include <setjmp.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 24 matching lines @@
 
 void ErrorExit(jpeg_common_struct* cinfo) {
   CoderErrorMgr *err = reinterpret_cast<CoderErrorMgr*>(cinfo->err);
 
   // Return control to the setjmp point.
   longjmp(err->setjmp_buffer, false);
 }
 
 }  // namespace
 
+// This method helps identify at run time which library chromium is using.
+JPEGCodec::LibraryVariant JPEGCodec::JpegLibraryVariant() {
+#if defined(USE_SYSTEM_LIBJPEG)
+  return SYSTEM_LIBJPEG;
+#elif defined(USE_LIBJPEG_TURBO)
+  return LIBJPEG_TURBO;
+#else
+  return IJG_LIBJPEG;
+#endif
+}
+
 // Encoder ---------------------------------------------------------------------
 //
 // This code is based on nsJPEGEncoder from Mozilla.
 // Copyright 2005 Google Inc. (Brett Wilson, contributor)
 
 namespace {
 
 // Initial size for the output buffer in the JpegEncoderState below.
 static const int initial_output_buffer_size = 8192;
 
@@ skipping 546 matching lines @@
 
   SkBitmap* bitmap = new SkBitmap();
   bitmap->setConfig(SkBitmap::kARGB_8888_Config, w, h);
   bitmap->allocPixels();
   memcpy(bitmap->getAddr32(0, 0), &data_vector[0], data_length);
 
   return bitmap;
 }
 
 }  // namespace gfx