Makes sure the keyboard typing isn't blocked when InputMethod::OnFocus() is not correctly called.

ui/base/ime/input_method_log_collector.h

Index: ui/base/ime/input_method_log_collector.h
diff --git a/ui/base/ime/input_method_log_collector.h b/ui/base/ime/input_method_log_collector.h
new file mode 100644
index 0000000000000000000000000000000000000000..7c6946032b9ca58d86fad2bd427e2a55c10b9be1
--- /dev/null
+++ b/ui/base/ime/input_method_log_collector.h
@@ -0,0 +1,29 @@
+// 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 UI_BASE_IME_INPUT_METHOD_LOG_COLLECTOR_H_
+#define UI_BASE_IME_INPUT_METHOD_LOG_COLLECTOR_H_
+
+#include <string>
+#include <vector>
+
+#include "ui/base/ime/ui_base_ime_export.h"
+
+namespace ui {
+
+class UI_BASE_IME_EXPORT InputMethodLogCollector {
+ public:
+  InputMethodLogCollector();
+  virtual ~InputMethodLogCollector();
+  void AddLog(const std::string& log_string);
+  void DumpLogs();
+  void ClearLogs();
+
+ private:
+  std::vector<std::string> logs_;

[eroman, 2016/01/13 22:27:08]

A couple design comments:

(1) How about making this a vector of string literals instead:
   std::vector<const char*> logs_;

From reading the callers of AddLog(), they all just pass string literals (except
for 2 callers which stringize a boolean, but that is easily changed into one of
two string literals).

The advantage of making them string literals is less memory overhead for
maintaining this log, and for copying the data to the stack (will be sufficient
to copy the literal pointers, as the literal content will be part of the binary
and easily recoverable).

(2) How large can logs_ grow? I am not very familiar with the surrounding code,
but I suggest putting in some defensive code to prevent the logs_ vector from
growing beyond a certain amount (maybe 10 or 20 is sufficient)? Provided the
content is string literals rather than std::string it is easy to predict the
worst case memory usage now.

[Shu Chen, 2016/01/14 07:44:47]

Makes sense. I've followed your suggestions.

+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_IME_INPUT_METHOD_LOG_COLLECTOR_H_