Combine the WM_CHAR with WM_KEY* for key event flow.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 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 "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
 
+#include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/memory/singleton.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "cc/base/switches.h"
 #include "chrome/browser/flags_storage.h"
@@ skipping 2100 matching lines @@
      kOsAndroid,
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableNTPPopularSites,
                                switches::kDisableNTPPopularSites)},
 #endif  // defined(OS_ANDROID)
 #if defined(OS_WIN)
      {"trace-export-events-to-etw",
       IDS_FLAGS_TRACE_EXPORT_EVENTS_TO_ETW_NAME,
       IDS_FLAGS_TRACE_EXPORT_EVENTS_TO_ETW_DESRIPTION,
       kOsWin,
       SINGLE_VALUE_TYPE(switches::kTraceExportEventsToETW)},
+    {"disable-merge-key-char-events",
+     IDS_FLAGS_DISABLE_MERGE_KEY_CHAR_EVENTS_NAME,

[yukawa, 2015/08/19 06:17:52]

If ENABLE_DISABLE_VALUE_TYPE works, can we rename this as
IDS_FLAGS_MERGE_KEY_CHAR_EVENTS_NAME?

[Shu Chen, 2015/08/19 06:41:31]

Done.

+     IDS_FLAGS_DISABLE_MERGE_KEY_CHAR_EVENTS_DESCRIPTION,
+     kOsWin,
+     SINGLE_VALUE_TYPE(switches::kDisableMergeKeyCharEvents)},

[yukawa, 2015/08/19 06:17:52]

I'm not familiar with this, but would it be possible to use
ENABLE_DISABLE_VALUE_TYPE?

[Shu Chen, 2015/08/19 06:41:31]

Done.

 #endif  // defined(OS_WIN)
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms.xml. See note in
     // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.
 };
 
 const Experiment* experiments = kExperiments;
 size_t num_experiments = arraysize(kExperiments);
 
 // Stores and encapsulates the little state that about:flags has.
@@ skipping 623 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags