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

chrome/app/chrome_main_delegate.cc

Index: chrome/app/chrome_main_delegate.cc
diff --git a/chrome/app/chrome_main_delegate.cc b/chrome/app/chrome_main_delegate.cc
index f75032eafb5288f2000f6d517121e80374af2934..579874df8bd9f2d5e6ea7055a393f86f52c99af8 100644
--- a/chrome/app/chrome_main_delegate.cc
+++ b/chrome/app/chrome_main_delegate.cc
@@ -667,7 +667,8 @@ void ChromeMainDelegate::PreSandboxStartup() {
     int locale_pak_fd = base::GlobalDescriptors::GetInstance()->MaybeGet(
         kAndroidLocalePakDescriptor);
     CHECK(locale_pak_fd != -1);
-    ResourceBundle::InitSharedInstanceWithPakFile(locale_pak_fd, false);
+    ResourceBundle::InitSharedInstanceWithPakFile(base::File(locale_pak_fd),
+                                                  false);

[cpu_(ooo_6.6-7.5), 2013/12/21 23:06:28]

so locale_pak_fd will be closed at this point since the temporary File object of
line 670 went out of scope. Is that ok?

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

The file is effectively passed to ResourceBundle, and from there to DataPack who
uses it to initialize a MemoryMappedFile (it will not be closed when this line
goes out of scope).

What I have to verify with someone familiar with this code is that
base::GlobalDescriptors::GetInstance()->MaybeGet is OK with the file being
closed by someone else (it would be better to return File(s) instead)... but
this particular change is not modifying that behavior.

[rvargas (doing something else), 2013/12/28 02:30:37]

Filed bug 330930, because GlobalDescriptors doesn't consider that case.

 
     int extra_pak_keys[] = {
       kAndroidChrome100PercentPakDescriptor,
@@ -678,7 +679,7 @@ void ChromeMainDelegate::PreSandboxStartup() {
           base::GlobalDescriptors::GetInstance()->MaybeGet(extra_pak_keys[i]);
       CHECK(pak_fd != -1);
       ResourceBundle::GetSharedInstance().AddDataPackFromFile(
-          pak_fd, ui::SCALE_FACTOR_100P);
+          base::File(pak_fd), ui::SCALE_FACTOR_100P);
     }
 
     base::i18n::SetICUDefaultLocale(locale);