Add UMA to measure time to open hyphenation dictionary

content/browser/hyphenation/hyphenation_impl.cc

 // 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.
 
 #include "content/browser/hyphenation/hyphenation_impl.h"
 
 #include <algorithm>
 #include <map>
 #include <utility>
 
 #include "base/files/file.h"
 #include "base/files/file_path.h"
+#include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
+#include "base/timer/elapsed_timer.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "mojo/public/cpp/system/platform_handle.h"
 
 namespace {
 
 using DictionaryFileMap = std::unordered_map<std::string, base::File>;
 
 static bool IsValidLocale(const std::string& locale) {
   return std::all_of(locale.cbegin(), locale.cend(), [](const char ch) {
     return base::IsAsciiAlpha(ch) || base::IsAsciiDigit(ch) || ch == '-';
@@ skipping 11 matching lines @@
   base::File& file = inserted.first->second;
   DCHECK(!file.IsValid());
 
 #if defined(OS_ANDROID)
   base::FilePath dir("/system/usr/hyphen-data");
 #else
 #error "This configuration is not supported."
 #endif
   std::string filename = base::StringPrintf("hyph-%s.hyb", locale.c_str());
   base::FilePath path = dir.AppendASCII(filename);
+  base::ElapsedTimer timer;
   file.Initialize(path, base::File::FLAG_OPEN | base::File::FLAG_READ);
+  UMA_HISTOGRAM_TIMES("Hyphenation.Open.File", timer.Elapsed());
   return file;
 }
 
 }  // namespace
 
 namespace hyphenation {
 
 HyphenationImpl::HyphenationImpl() {}
 
 HyphenationImpl::~HyphenationImpl() {}
 
 // static
 void HyphenationImpl::Create(blink::mojom::HyphenationRequest request) {
   mojo::MakeStrongBinding(base::MakeUnique<HyphenationImpl>(),
                           std::move(request));
 }
 
 void HyphenationImpl::OpenDictionary(const mojo::String& locale,
                                      const OpenDictionaryCallback& callback) {
   mojo::ScopedHandle handle;
   if (IsValidLocale(locale)) {
     base::File& file = GetDictionaryFile(locale);
     if (file.IsValid())
       handle = mojo::WrapPlatformFile(file.Duplicate().TakePlatformFile());
   }
   callback.Run(std::move(handle));
 }
 
 }  // namespace hyphenation