[translate] Add translate ranker model loader.

base/metrics/histogram_macros_internal.h

Index: base/metrics/histogram_macros_internal.h
diff --git a/base/metrics/histogram_macros_internal.h b/base/metrics/histogram_macros_internal.h
index 2deb9284a177fa26a4e3ecdd155addcb96422f6e..13990f8bfbd7c6bfd147b20cee51e1f44b073a04 100644
--- a/base/metrics/histogram_macros_internal.h
+++ b/base/metrics/histogram_macros_internal.h
@@ -104,8 +104,9 @@
     static_assert(                                                             \
         !std::is_enum<decltype(sample)>::value ||                              \
             !std::is_enum<decltype(boundary)>::value ||                        \
-            std::is_same<std::remove_const<decltype(sample)>::type,            \
-                         std::remove_const<decltype(boundary)>::type>::value,  \
+            std::is_same<                                                      \
+                typename std::remove_const<decltype(sample)>::type,            \

[pasko, 2016/12/19 14:26:49]

please explain why this is relevant to this change

[Roger McFarlane (Chromium), 2017/02/08 23:08:07]

This macro cannot be used to reference template params inside a template
decl/def without this.

If std::remove_const<decltype(Foo)>::type is a dependent name, it requires
typename or it fails to compile; otherwise, it's optional.

C++ standard, section 14.6:
A name used in a template declaration or definition and that is dependent on a
template-parameter is assumed not to name a type unless the applicable name
lookup finds a type name or the name is qualified by the keyword typename.

+                typename std::remove_const<decltype(boundary)>::type>::value,  \
         "|sample| and |boundary| shouldn't be of different enums");            \
     STATIC_HISTOGRAM_POINTER_BLOCK(                                            \
         name, Add(sample), base::LinearHistogram::FactoryGet(                  \