Creating class for processing of keypress events.

components/password_manager/core/browser/password_reuse_detection_manager.cc

Index: components/password_manager/core/browser/password_reuse_detection_manager.cc
diff --git a/components/password_manager/core/browser/password_reuse_detection_manager.cc b/components/password_manager/core/browser/password_reuse_detection_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8063d739925ae2a3bb8146624cb80d6e6607a0d9
--- /dev/null
+++ b/components/password_manager/core/browser/password_reuse_detection_manager.cc
@@ -0,0 +1,35 @@
+// Copyright (c) 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 "components/password_manager/core/browser/password_reuse_detection_manager.h"
+
+#include "components/password_manager/core/browser/password_manager_client.h"
+
+namespace password_manager {
+
+namespace {
+const size_t kMaxNumberOfCharactersToStore = 30;

[vabr (Chromium), 2016/12/23 17:14:11]

constexpr

[dvadym, 2016/12/23 17:45:20]

Done.

+}
+
+PasswordReuseDetectionManager::PasswordReuseDetectionManager(
+    PasswordManagerClient* client)
+    : client_(client) {
+  DCHECK(client_);
+}
+
+PasswordReuseDetectionManager::~PasswordReuseDetectionManager() {}
+
+void PasswordReuseDetectionManager::DidNavigateMainFrame() {
+  input_characters_.clear();
+}
+
+void PasswordReuseDetectionManager::OnKeyPressed(const base::string16& text) {
+  input_characters_ += text;
+  if (input_characters_.size() > kMaxNumberOfCharactersToStore)
+    input_characters_.erase(

[vabr (Chromium), 2016/12/23 17:14:11]

This is fairly inefficient -- with every key stroke (except the first 29), the
whole buffer gets shifted. Instead we should use a cyclic buffer (no shifting at
all), and modify PasswordReuseDetector::CheckReuse to work with that. With
https://crbug.com/668155 in mind, we could even populate the cyclic buffer here
in a reverse manner, to spare computing the reverse in
PasswordReuseDetector::CheckReuse.

I'm aware that your plan was to get a simple version going and apply
optimisations after that. But unlike in the last case
(https://crbug.com/668155), the code here will start processing in Chrome
already.

So either let's do the cyclic buffer, or don't save stuff at all until the
optimised solution is ready.

[dvadym, 2016/12/23 17:45:20]

Good point. I think that cyclic buffer is the best solution here. I've removed
storing text for now and I'll implement cyclic buffer in next CL.

+        0, input_characters_.size() - kMaxNumberOfCharactersToStore);
+  // TODO(dvadym): Implement here asking a store about password reuse.
+}
+
+}  // namespace password_manager