Revert of Implement ScopedFD in terms of ScopedGeneric. (https://codereview.chromium.org/191673003/)

Reason for revert:
Doesn't build on android:

FAILED: /mnt/data/b/build/goma/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF obj/base/memory/base.discardable_memory_allocator_android.o.d -DV8_DEPRECATION_WARNINGS -DBLINK_SCALE_FILTERS_AT_RECORD_TIME -D_FILE_OFFSET_BITS=64 -DNO_TCMALLOC -DDISABLE_NACL -DCHROMIUM_BUILD -DCOMPONENT_BUILD -DUSE_LIBJPEG_TURBO=1 -DENABLE_WEBRTC=1 -DUSE_PROPRIETARY_CODECS -DENABLE_CONFIGURATION_POLICY -DENABLE_NEW_GAMEPAD_API=1 -DDISCARDABLE_MEMORY_ALWAYS_SUPPORTED_NATIVELY -DSYSTEM_NATIVELY_SIGNALS_MEMORY_PRESSURE -DENABLE_EGLIMAGE=1 -DENABLE_AUTOFILL_DIALOG=1 -DCLD_VERSION=1 -DENABLE_PRINTING=1 -DENABLE_MANAGED_USERS=1 -DUSE_OPENSSL=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DBASE_IMPLEMENTATION -DANDROID -D__GNU_SOURCE=1 -DUSE_STLPORT=1 -D_STLP_USE_PTR_SPECIALIZATIONS=1 '-DCHROME_BUILD_ID=""' -DHAVE_SYS_UIO_H -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DWTF_USE_DYNAMIC_ANNOTATIONS=1 -D_DEBUG -Igen/base -I../../third_party/android_tools/ndk/sources/android/cpufeatures -I../.. -fstack-protector --param=ssp-buffer-size=4 -Werror -fno-exceptions -fno-strict-aliasing -Wall -Wno-unused-parameter -Wno-missing-field-initializers -fvisibility=hidden -pipe -fPIC -Wheader-hygiene -Wno-char-subscripts -Wno-unneeded-internal-declaration -Wno-covered-switch-default -Wstring-conversion -Wno-c++11-narrowing -Wno-reserved-user-defined-literal -Wno-deprecated-register -Xclang -load -Xclang /mnt/data/b/build/slave/Android_Clang_Builder__dbg_/build/src/tools/clang/scripts/../../../third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.so -Xclang -add-plugin -Xclang find-bad-constructs -Xclang -plugin-arg-find-bad-constructs -Xclang check-url-directory -fcolor-diagnostics -Wexit-time-destructors -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=softfp -mthumb -no-integrated-as -B/mnt/data/b/build/slave/Android_Clang_Builder__dbg_/build/src/third_party/android_tools/ndk//toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86_64/bin -ffunction-sections -funwind-tables -g -fstack-protector -fno-short-enums -Wa,--noexecstack -D__compiler_offsetof=__builtin_offsetof -Dnan=__builtin_nan -target arm-linux-androideabi -mllvm -arm-enable-ehabi --sysroot=/mnt/data/b/build/slave/Android_Clang_Builder__dbg_/build/src/third_party/android_tools/ndk//platforms/android-14/arch-arm -I/mnt/data/b/build/slave/Android_Clang_Builder__dbg_/build/src/third_party/android_tools/ndk//sources/cxx-stl/stlport/stlport -Os -g -fomit-frame-pointer -fdata-sections -ffunction-sections -funwind-tables -g0 -fno-rtti -fno-threadsafe-statics -fvisibility-inlines-hidden -Wsign-compare -std=gnu++11 -Wno-implicit-exception-spec-mismatch -Wno-abi  -c ../../base/memory/discardable_memory_allocator_android.cc -o obj/base/memory/base.discardable_memory_allocator_android.o
../../base/memory/discardable_memory_allocator_android.cc:84:25:error: no matching function for call to 'mmap'
  void* const address = mmap(
                        ^~~~
/mnt/data/b/build/slave/Android_Clang_Builder__dbg_/build/src/third_party/android_tools/ndk//platforms/android-14/arch-arm/usr/include/sys/mman.h:47:15: note: candidate function not viable: no known conversion from 'base::ScopedFD' (aka 'ScopedGeneric<int, internal::ScopedFDCloseTraits>') to 'int' for 5th argument
extern void*  mmap(void *, size_t, int, int, int, off_t);
              ^
1 error generated.

Original issue's description:
> Implement ScopedFD in terms of ScopedGeneric.
> 
> Move to a new file base/files/scoped_file.h. I will also add ScopedFILE to here (currently in file_util.h) later.
> 
> I think there is a crash in the old code in content/browser/zygote_host/zygote_host_impl_linux.cc that this patch should fix. The old ScopedFD took the address of something in a vector that is being modified.
> 
> I removed SafeScopedFD from content/common/sandbox_linux/sandbox_linux.cc since base's ScopedFD not CHECKs on close failure (this is a more recent addition).
> 
> BUG=
> R=agl@chromium.org, viettrungluu@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=257001

TBR=viettrungluu@chromium.org,agl@chromium.org,brettw@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/197873014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257005 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 21 insertions, 17 deletions

diff --git a/base/memory/discardable_memory_allocator_android.cc b/base/memory/discardable_memory_allocator_android.cc
index b1c936a..97e9abd 100644
--- a/base/memory/discardable_memory_allocator_android.cc
+++ b/base/memory/discardable_memory_allocator_android.cc
@@ -16,7 +16,6 @@
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/file_util.h"
-#include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/memory/discardable_memory.h"
 #include "base/memory/scoped_vector.h"
@@ -66,13 +65,14 @@ bool CreateAshmemRegion(const char* name,
                         size_t size,
                         int* out_fd,
                         void** out_address) {
-  base::ScopedFD fd(ashmem_create_region(name, size));
-  if (!fd.is_valid()) {
+  int fd = ashmem_create_region(name, size);
+  if (fd < 0) {
     DLOG(ERROR) << "ashmem_create_region() failed";
     return false;
   }
+  file_util::ScopedFD fd_closer(&fd);
 
-  const int err = ashmem_set_prot_region(fd.get(), PROT_READ | PROT_WRITE);
+  const int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE);
   if (err < 0) {
     DLOG(ERROR) << "Error " << err << " when setting protection of ashmem";
     return false;
@@ -88,7 +88,8 @@ bool CreateAshmemRegion(const char* name,
     return false;
   }
 
-  *out_fd = fd.release();
+  ignore_result(fd_closer.release());
+  *out_fd = fd;
   *out_address = address;
   return true;
 }
diff --git a/base/memory/shared_memory.h b/base/memory/shared_memory.h
index 8e32e72..50b61c4 100644
--- a/base/memory/shared_memory.h
+++ b/base/memory/shared_memory.h
@@ -22,7 +22,6 @@
 #if defined(OS_POSIX)
 #include "base/file_descriptor_posix.h"
 #include "base/file_util.h"
-#include "base/files/scoped_file.h"
 #endif
 
 namespace base {
@@ -260,7 +259,7 @@ class BASE_EXPORT SharedMemory {
 
  private:
 #if defined(OS_POSIX) && !defined(OS_NACL)
-  bool PrepareMapFile(file_util::ScopedFILE fp, base::ScopedFD readonly);
+  bool PrepareMapFile(file_util::ScopedFILE fp, file_util::ScopedFD readonly);
   bool FilePathForMemoryName(const std::string& mem_name, FilePath* path);
   void LockOrUnlockCommon(int function);
 #endif
diff --git a/base/memory/shared_memory_posix.cc b/base/memory/shared_memory_posix.cc
index 1a90847..8780c04 100644
--- a/base/memory/shared_memory_posix.cc
+++ b/base/memory/shared_memory_posix.cc
@@ -30,6 +30,7 @@
 #include "third_party/ashmem/ashmem.h"
 #endif
 
+using file_util::ScopedFD;
 using file_util::ScopedFILE;
 
 namespace base {
@@ -131,7 +132,8 @@ bool SharedMemory::Create(const SharedMemoryCreateOptions& options) {
 
   ScopedFILE fp;
   bool fix_size = true;
-  ScopedFD readonly_fd;
+  int readonly_fd_storage = -1;
+  ScopedFD readonly_fd(&readonly_fd_storage);
 
   FilePath path;
   if (options.name_deprecated == NULL || options.name_deprecated->empty()) {
@@ -143,8 +145,8 @@ bool SharedMemory::Create(const SharedMemoryCreateOptions& options) {
 
     if (fp) {
       // Also open as readonly so that we can ShareReadOnlyToProcess.
-      readonly_fd.reset(HANDLE_EINTR(open(path.value().c_str(), O_RDONLY)));
-      if (!readonly_fd.is_valid()) {
+      *readonly_fd = HANDLE_EINTR(open(path.value().c_str(), O_RDONLY));
+      if (*readonly_fd < 0) {
         DPLOG(ERROR) << "open(\"" << path.value() << "\", O_RDONLY) failed";
         fp.reset();
       }
@@ -196,8 +198,8 @@ bool SharedMemory::Create(const SharedMemoryCreateOptions& options) {
     }
 
     // Also open as readonly so that we can ShareReadOnlyToProcess.
-    readonly_fd.reset(HANDLE_EINTR(open(path.value().c_str(), O_RDONLY)));
-    if (!readonly_fd.is_valid()) {
+    *readonly_fd = HANDLE_EINTR(open(path.value().c_str(), O_RDONLY));
+    if (*readonly_fd < 0) {
       DPLOG(ERROR) << "open(\"" << path.value() << "\", O_RDONLY) failed";
       close(fd);
       fd = -1;
@@ -263,8 +265,10 @@ bool SharedMemory::Open(const std::string& name, bool read_only) {
 
   const char *mode = read_only ? "r" : "r+";
   ScopedFILE fp(base::OpenFile(path, mode));
-  ScopedFD readonly_fd(HANDLE_EINTR(open(path.value().c_str(), O_RDONLY)));
-  if (!readonly_fd.is_valid()) {
+  int readonly_fd_storage = -1;
+  ScopedFD readonly_fd(&readonly_fd_storage);
+  *readonly_fd = HANDLE_EINTR(open(path.value().c_str(), O_RDONLY));
+  if (*readonly_fd < 0) {
     DPLOG(ERROR) << "open(\"" << path.value() << "\", O_RDONLY) failed";
   }
   return PrepareMapFile(fp.Pass(), readonly_fd.Pass());
@@ -349,7 +353,7 @@ void SharedMemory::UnlockDeprecated() {
 bool SharedMemory::PrepareMapFile(ScopedFILE fp, ScopedFD readonly_fd) {
   DCHECK_EQ(-1, mapped_file_);
   DCHECK_EQ(-1, readonly_mapped_file_);
-  if (fp == NULL || !readonly_fd.is_valid()) return false;
+  if (fp == NULL || *readonly_fd < 0) return false;
 
   // This function theoretically can block on the disk, but realistically
   // the temporary files we create will just go into the buffer cache
@@ -360,7 +364,7 @@ bool SharedMemory::PrepareMapFile(ScopedFILE fp, ScopedFD readonly_fd) {
   struct stat readonly_st = {};
   if (fstat(fileno(fp.get()), &st))
     NOTREACHED();
-  if (fstat(readonly_fd.get(), &readonly_st))
+  if (fstat(*readonly_fd, &readonly_st))
     NOTREACHED();
   if (st.st_dev != readonly_st.st_dev || st.st_ino != readonly_st.st_ino) {
     LOG(ERROR) << "writable and read-only inodes don't match; bailing";
@@ -377,7 +381,7 @@ bool SharedMemory::PrepareMapFile(ScopedFILE fp, ScopedFD readonly_fd) {
     }
   }
   inode_ = st.st_ino;
-  readonly_mapped_file_ = readonly_fd.release();
+  readonly_mapped_file_ = *readonly_fd.release();
 
   return true;
 }