Revert "Intercept base::File Open/Close"

This reverts commit 45a0dc0b75b52e026eb15526ef441edc5dbe9ba5.
> Intercept base::File Open/Close
>
> When a file descriptor is opened by the base::File, all calls to close(3) from
> the same dynamic library will hit a CHECK unless they are made from a
> whitelist of callsites belonging to base::File.
>
> There is a handy protect_file_posix.gypi introduced to make it easy to enable
> on Chrome-for-Android.
>
> This 'linker magic' is somewhat crazy, so:
> 1. it will be *removed *when crbug.com/424562 is fixed
> 2. it should only be used by a whitelist of binaries/libraries (in the
>    opensource part: libchromeshell only)
>
> BUG=424562
>
> Review URL: https://codereview.chromium.org/676873004
>
> Cr-Commit-Position: refs/heads/master@{#304592}

Reason: crashes are not numerous, not much sense to fix, some explanations found
elsewhere.

BUG=424562

Review URL: https://codereview.chromium.org/1101723004

Cr-Commit-Position: refs/heads/master@{#327051}


CrOS-Libchrome-Original-Commit: e1ceecf5545568261956de95fda59270a91d4ef0
diff --git a/base/files/file_posix.cc b/base/files/file_posix.cc
index dab9cc2..4c79057 100644
--- a/base/files/file_posix.cc
+++ b/base/files/file_posix.cc
@@ -10,7 +10,6 @@
 #include <unistd.h>
 
 #include "base/files/file_path.h"
-#include "base/files/file_posix_hooks_internal.h"
 #include "base/logging.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/posix/eintr_wrapper.h"
@@ -158,14 +157,6 @@
                                   Time::kNanosecondsPerMicrosecond);
 }
 
-// Default implementations of Protect/Unprotect hooks defined as weak symbols
-// where possible.
-void ProtectFileDescriptor(int fd) {
-}
-
-void UnprotectFileDescriptor(int fd) {
-}
-
 bool File::IsValid() const {
   return file_.is_valid();
 }
@@ -175,8 +166,6 @@
 }
 
 PlatformFile File::TakePlatformFile() {
-  if (IsValid())
-    UnprotectFileDescriptor(GetPlatformFile());
   return file_.release();
 }
 
@@ -185,7 +174,6 @@
     return;
 
   ThreadRestrictions::AssertIOAllowed();
-  UnprotectFileDescriptor(GetPlatformFile());
   file_.reset();
 }
 
@@ -537,7 +525,6 @@
   async_ = ((flags & FLAG_ASYNC) == FLAG_ASYNC);
   error_details_ = FILE_OK;
   file_.reset(descriptor);
-  ProtectFileDescriptor(descriptor);
 }
 #endif  // !defined(OS_NACL)
 
@@ -555,10 +542,8 @@
 }
 
 void File::SetPlatformFile(PlatformFile file) {
-  CHECK(!file_.is_valid());
+  DCHECK(!file_.is_valid());
   file_.reset(file);
-  if (file_.is_valid())
-    ProtectFileDescriptor(GetPlatformFile());
 }
 
 }  // namespace base