Re-enable pre-read experiment as a finch field trial.

chrome/app/image_pre_reader_win.h

 // 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.
 
 // This file defines utility functions to pre-read a PE Image in order to
 // avoid hard page faults when the image is subsequently loaded into memory
 // for execution.
 
 #ifndef CHROME_APP_IMAGE_PRE_READER_WIN_H_
 #define CHROME_APP_IMAGE_PRE_READER_WIN_H_
@@ skipping 35 matching lines @@
   //
   // The max_chunk_size indicates the number of bytes to read off the disk in
   // each step (for Vista and greater, where this is the way the pages are
   // warmed).
   //
   // This function is intended to be used in the context of a PE image with
   // an optimized layout, such that the blocks in each section are arranged
   // with the data and code most needed for startup moved to the front.
   // See also: http://code.google.com/p/chromium/issues/detail?id=98508
   static bool PartialPreReadImage(const wchar_t* file_path,
-                                  uint8 percentage,
+                                  size_t percentage,
                                   size_t max_chunk_size);
 
   // Helper function used by PartialPreReadImage on Windows versions (Vista+)
   // where reading through the file on disk serves to warm up the page cache.
   // Exported for unit-testing purposes.
   static bool PartialPreReadImageOnDisk(const wchar_t* file_path,
-                                        uint8 percentage,
+                                        size_t percentage,
                                         size_t max_chunk_size);
 
   // Helper function used by PartialPreReadImage on Windows versions (XP) where
   // cheaply loading the image then stepping through its address space serves
   // to warm up the page cache. Exported for unit-testing purposes.
   static bool PartialPreReadImageInMemory(const wchar_t* file_path,
-                                          uint8 percentage);
+                                          size_t percentage);
 };  // namespace internal
 
 #endif  // CHROME_APP_IMAGE_PRE_READER_WIN_H_