Views::Textfield: Prevent revealing password text.

ui/views/controls/textfield/textfield_model.cc

Index: ui/views/controls/textfield/textfield_model.cc
diff --git a/ui/views/controls/textfield/textfield_model.cc b/ui/views/controls/textfield/textfield_model.cc
index 5738887b7256d5c84e2aa333472fae50bc42ec25..a89c3cc99aa9ae0d48a321b85faef35ef54e74a0 100644
--- a/ui/views/controls/textfield/textfield_model.cc
+++ b/ui/views/controls/textfield/textfield_model.cc
@@ -344,11 +344,15 @@ void TextfieldModel::Append(const base::string16& new_text) {
 }
 
 bool TextfieldModel::Delete(bool add_to_kill_buffer) {
+  // |add_to_kill_buffer| should never be true for an obscured textfield.
+  DCHECK(!add_to_kill_buffer || !render_text_->obscured());
+
   if (HasCompositionText()) {
     // No undo/redo for composition text.
     CancelCompositionText();
     return true;
   }
+
   if (HasSelection()) {
     if (add_to_kill_buffer)
       SetKillBuffer(GetSelectedText());
@@ -369,11 +373,15 @@ bool TextfieldModel::Delete(bool add_to_kill_buffer) {
 }
 
 bool TextfieldModel::Backspace(bool add_to_kill_buffer) {
+  // |add_to_kill_buffer| should never be true for an obscured textfield.
+  DCHECK(!add_to_kill_buffer || !render_text_->obscured());
+
   if (HasCompositionText()) {
     // No undo/redo for composition text.
     CancelCompositionText();
     return true;
   }
+
   if (HasSelection()) {
     if (add_to_kill_buffer)
       SetKillBuffer(GetSelectedText());
@@ -430,8 +438,7 @@ bool TextfieldModel::MoveCursorTo(const gfx::Point& point, bool select) {
 }
 
 base::string16 TextfieldModel::GetSelectedText() const {
-  return text().substr(render_text_->selection().GetMin(),
-                       render_text_->selection().length());
+  return GetTextFromRange(render_text_->selection());
 }
 
 void TextfieldModel::SelectRange(const gfx::Range& range) {