Revert of Disable implicit conversions of scoped_refptr to T* on CrOS.

Revert of Disable implicit conversions of scoped_refptr to T* on CrOS. (patchset #1 id:1 of https://codereview.chromium.org/572713003/)

Reason for revert:
Broke "compile" on http://build.chromium.org/p/chromium.chrome/builders/Google%20Chrome%20ChromeOS/builds/71959

FAILED: /b/build/goma/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF obj/chrome/browser/chromeos/login/session/browser_chromeos.user_session_manager.o.d -DV8_DEPRECATION_WARNINGS -D_FILE_OFFSET_BITS=64 -DGOOGLE_CHROME_BUILD -DCR_CLANG_REVISION=214024 -DENABLE_RLZ -DTOOLKIT_VIEWS=1 -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_ASH=1 -DUSE_PANGO=1 -DUSE_CAIRO=1 -DUSE_GLIB=1 -DUSE_DEFAULT_RENDER_THEME=1 -DUSE_X11=1 -DUSE_XI2_MT=2 -DIMAGE_LOADER_EXTENSION=1 -DENABLE_REMOTING=1 -DENABLE_WEBRTC=1 -DUSE_PROPRIETARY_CODECS -DENABLE_PEPPER_CDMS -DENABLE_CONFIGURATION_POLICY -DENABLE_NOTIFICATIONS -DENABLE_HIDPI=1 -DUSE_UDEV -DENABLE_EGLIMAGE=1 -DENABLE_TASK_MANAGER=1 -DENABLE_EXTENSIONS=1 -DENABLE_PLUGINS=1 -DENABLE_SESSION_SERVICE=1 -DENABLE_THEMES=1 -DENABLE_AUTOFILL_DIALOG=1 -DENABLE_PROD_WALLET_SERVICE=1 -DENABLE_BACKGROUND=1 -DENABLE_GOOGLE_NOW=1 -DCLD_VERSION=2 -DCLD2_DATA_SOURCE=static -DENABLE_FULL_PRINTING=1 -DENABLE_PRINTING=1 -DENABLE_SPELLCHECK=1 -DENABLE_CAPTIVE_PORTAL_DETECTION=1 -DENABLE_APP_LIST=1 -DENABLE_MANAGED_USERS=1 -DENABLE_MDNS=1 -DENABLE_SERVICE_DISCOVERY=1 -DENABLE_LOAD_COMPLETION_HACKS=1 -DNACL_WINDOWS=0 -DNACL_LINUX=1 -DNACL_OSX=0 -DNACL_ANDROID=0 -DNACL_TARGET_SUBARCH=64 -DNACL_TARGET_ARCH=x86 -DNACL_BUILD_SUBARCH=64 -DNACL_BUILD_ARCH=x86 -DGL_GLEXT_PROTOTYPES -DMOJO_USE_SYSTEM_IMPL -DLIBPEERCONNECTION_LIB=1 -DUSE_BRLAPI -DSK_ENABLE_INST_COUNT=0 -DSK_SUPPORT_GPU=1 '-DGR_GL_CUSTOM_SETUP_HEADER="GrGLConfig_chrome.h"' -DSK_ENABLE_LEGACY_API_ALIASING=1 -DSK_ATTR_DEPRECATED=SK_NOTHING_ARG1 -DGR_GL_IGNORE_ES3_MSAA=0 -DSK_WILL_NEVER_DRAW_PERSPECTIVE_TEXT -DSK_SUPPORT_LEGACY_PUBLIC_IMAGEINFO_FIELDS -DSK_IGNORE_PROPER_FRACTIONAL_SCALING -DSK_SUPPORT_LEGACY_PICTURE_CLONE -DSK_IGNORE_ETC1_SUPPORT -DSK_IGNORE_GPU_DITHER -DSK_SUPPORT_LEGACY_IMAGECACHE_NAME -DSK_LEGACY_PICTURE_SIZE_API -DSK_LEGACY_PICTURE_DRAW_API -DSK_USE_POSIX_THREADS -DSK_DEFERRED_CANVAS_USES_FACTORIES=1 -DHUNSPELL_STATIC -DHUNSPELL_CHROME_CLIENT -DUSE_HUNSPELL -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DU_STATIC_IMPLEMENTATION -DFEATURE_ENABLE_SSL -DFEATURE_ENABLE_VOICEMAIL -DEXPAT_RELATIVE_PATH -DGTEST_RELATIVE_PATH -DNO_MAIN_THREAD_WRAPPING -DNO_SOUND_SYSTEM -DLINUX -DWEBRTC_LINUX -DPOSIX -DWEBRTC_POSIX -DCHROMEOS -DLIBXML_STATIC -DPROTOBUF_USE_DLLS -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DUSE_NSS=1 -DOS_CHROMEOS=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DOFFICIAL_BUILD -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -D_FORTIFY_SOURCE=2 -Igen -I../../breakpad/src -Iobj/chrome/browser_chromeos.gen -Iobj/chrome/browser_chromeos.gen/chrome -I../.. -I../../skia/config -I../../third_party/khronos -I../../gpu -I../../third_party/WebKit/Source -Igen/angle -Igen/protoc_out -Igen/chrome -Igen/policy -Igen/components/strings -Igen/content/app/resources/ -I../../third_party/WebKit -I../../net/third_party/nss/ssl -I../../third_party/skia/src/core -I../../third_party/skia/include/core -I../../third_party/skia/include/effects -I../../third_party/skia/include/pdf -I../../third_party/skia/include/gpu -I../../third_party/skia/include/lazy -I../../third_party/skia/include/pathops -I../../third_party/skia/include/pipe -I../../third_party/skia/include/ports -I../../third_party/skia/include/utils -I../../skia/ext -I../../third_party/cacheinvalidation/overrides -I../../third_party/cacheinvalidation/src -I../../third_party/cacheinvalidation/google/cacheinvalidation -I../../third_party/icu/source/i18n -I../../third_party/icu/source/common -I../../third_party/leveldatabase/src/include -I../../third_party/leveldatabase/src -I../../third_party/leveldatabase -I../../third_party/webrtc/overrides -I../../third_party/libjingle/overrides -I../../third_party/libjingle/source -I../../testing/gtest/include -I../../third_party -I../../third_party/libusb/src/libusb -I../../third_party/libxml/linux/include -I../../third_party/libxml/src/include -I../../third_party/npapi -I../../third_party/npapi/bindings -I../../third_party/protobuf -I../../third_party/protobuf/src -I../../third_party/re2 -I../../third_party/zlib -Igen/ui/chromeos/resources -Igen/ui/chromeos/strings -Igen/ui/resources -I../../v8/include -Igen/ash/resources -Igen/ash/strings -Igen/ui/gl -I../../third_party/mesa/src/include -Werror -pthread -fno-strict-aliasing -Wall -Wno-unused-parameter -Wno-missing-field-initializers -fvisibility=hidden -pipe -fPIC -Wno-reserved-user-defined-literal -Xclang -load -Xclang /b/build/slave/google-chrome-rel-chromeos/build/src/tools/clang/scripts/../../../third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.so -Xclang -add-plugin -Xclang find-bad-constructs -fcolor-diagnostics -g -B/b/build/slave/google-chrome-rel-chromeos/build/src/third_party/binutils/Linux_x64/Release/bin -Wheader-hygiene -Wno-char-subscripts -Wno-unneeded-internal-declaration -Wno-covered-switch-default -Wstring-conversion -Wno-c++11-narrowing -Wno-deprecated-register -Wexit-time-destructors -pthread -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include -I/usr/include/nss -I/usr/include/nspr -Wno-header-guard -m64 -march=x86-64 -O2 -fno-ident -fdata-sections -ffunction-sections -fno-slp-vectorize -fno-unwind-tables -fno-asynchronous-unwind-tables -fno-exceptions -fno-rtti -fno-threadsafe-statics -fvisibility-inlines-hidden -Wsign-compare -std=gnu++11  -c ../../chrome/browser/chromeos/login/session/user_session_manager.cc -o obj/chrome/browser/chromeos/login/session/browser_chromeos.user_session_manager.o
../../chrome/browser/chromeos/login/session/user_session_manager.cc:321:3: error: no matching function for call to 'PostTaskAndReplyWithResult'
  base::PostTaskAndReplyWithResult(
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../base/task_runner_util.h:55:6: note: candidate function [with TaskReturnType = bool, ReplyArgType = bool] not viable: no known conversion from 'const scoped_refptr<base::TaskRunner>' to 'base::TaskRunner *' for 1st argument
bool PostTaskAndReplyWithResult(
     ^
1 error generated.
ninja: build stopped: subcommand failed.


Original issue's description:
> Disable implicit conversions of scoped_refptr to T* on CrOS.
> 
> The implicit conversion has already been disabled for Linux builds for
> some time now. https://codereview.chromium.org/510323002 explains the
> rationale for proceeding incrementally.
> 
> BUG=110610
> 
> Committed: https://crrev.com/1e6ba5a2c981b0b0c82d40e45e712c02480f2d6c
> Cr-Commit-Position: refs/heads/master@{#295234}

TBR=willchan@chromium.org,dcheng@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=110610

[horo, 2014-09-17 07:18:51]

Created Revert of Disable implicit conversions of scoped_refptr to T* on CrOS.

[horo, 2014-09-17 07:19:31]

The CQ bit was unchecked by horo@chromium.org