[translate] Add translate ranker model loader.

base/metrics/histogram_macros_internal.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_METRICS_HISTOGRAM_MACROS_INTERNAL_H_
 #define BASE_METRICS_HISTOGRAM_MACROS_INTERNAL_H_
 
 #include "base/atomicops.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ skipping 86 matching lines @@
 
 // This is a helper macro used by other macros and shouldn't be used directly.
 // One additional bucket is created in the LinearHistogram for the illegal
 // values >= boundary_value so that mistakes in calling the UMA enumeration
 // macros can be detected.
 #define INTERNAL_HISTOGRAM_ENUMERATION_WITH_FLAG(name, sample, boundary, flag) \
   do {                                                                         \
     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(                  \
                                name, 1, boundary, boundary + 1, flag));        \
   } while (0)
 
 // This is a helper macro used by other macros and shouldn't be used directly.
 // This is necessary to expand __COUNTER__ to an actual value.
 #define INTERNAL_SCOPED_UMA_HISTOGRAM_TIMER_EXPANDER(name, is_long, key)       \
   INTERNAL_SCOPED_UMA_HISTOGRAM_TIMER_UNIQUE(name, is_long, key)
@@ skipping 21 matching lines @@
 // may be more efficient in memory if the total number of sample values is small
 // compared to the range of their values.
 #define INTERNAL_HISTOGRAM_SPARSE_SLOWLY(name, sample)                         \
     do {                                                                       \
       base::HistogramBase* histogram = base::SparseHistogram::FactoryGet(      \
           name, base::HistogramBase::kUmaTargetedHistogramFlag);               \
       histogram->Add(sample);                                                  \
     } while (0)
 
 #endif  // BASE_METRICS_HISTOGRAM_MACROS_INTERNAL_H_