Convert base::MemoryMappedFile to use File instead of PlatformFile.

chrome/renderer/spellchecker/hunspell_engine.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/renderer/spellchecker/hunspell_engine.h"
 
 #include <algorithm>
 #include <iterator>
 
 #include "base/files/memory_mapped_file.h"
@@ skipping 43 matching lines @@
   file_ = file;
   // Delay the actual initialization of hunspell until it is needed.
 }
 
 void HunspellEngine::InitializeHunspell() {
   if (hunspell_.get())
     return;
 
   bdict_file_.reset(new base::MemoryMappedFile);
 
-  if (bdict_file_->Initialize(file_)) {
+  // TODO(rvargas): This object should not keep file_ after passing it to
+  // bdict_file_.

[groby-ooo-7-16, 2013/12/27 19:52:26]

If you want to address the TODO: file_, bdict_file_, initialized_ and
dictionary_requested_ together are used to coordinate a multi-stage
initialization. Relinquishing file_ might be tricky :)

(Stages are bare object, request dictionary, memory map dictionary & init
hunspell. The last 2 are on demand, when InitializeIfNeeded is called)

+  if (bdict_file_->Initialize(base::File(file_))) {

[groby-ooo-7-16, 2013/12/27 19:52:26]

Probably want file_ to be base::File, for clearer ownership semantics. (Also,
this fixes a file leak if InitializeHunspell is never called :)

[rvargas (doing something else), 2013/12/27 23:54:39]

That sounds correct. I didn't do it because it probably means changing Init (and
the callers) to pass File instead, and I don't know what would be the logic for
IsEnabled (cannot be file_.IsValid()). Besides, I'm trying to contain the scope
of this change.

Keeping the current type for file_ at least makes clear that this code has to be
updated.

     TimeTicks debug_start_time = base::Histogram::DebugNow();
 
     hunspell_.reset(
         new Hunspell(bdict_file_->data(), bdict_file_->length()));
 
     DHISTOGRAM_TIMES("Spellcheck.InitTime",
                      base::Histogram::DebugNow() - debug_start_time);
   } else {
     NOTREACHED() << "Could not mmap spellchecker dictionary.";
   }
@@ skipping 59 matching lines @@
   // Don't initialize if hunspell is disabled.
   if (file_ != base::kInvalidPlatformFileValue)
     InitializeHunspell();
 
   return !initialized_;
 }
 
 bool HunspellEngine::IsEnabled() {
   return file_ != base::kInvalidPlatformFileValue;
 }