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
SVN changes up to revision 257005