Combine the WM_CHAR with WM_KEY* for key event flow.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index ac3beae08058109ddd49442fbf903540423db7e7..da418b02a237238db4c958c2f20e9f402ad925bb 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -9,6 +9,7 @@
 #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"
@@ -2129,6 +2130,11 @@ const Experiment kExperiments[] = {
       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