Make NativeTextfieldViews update the win system caret.

ui/views/controls/textfield/native_textfield_views.cc

Index: ui/views/controls/textfield/native_textfield_views.cc
diff --git a/ui/views/controls/textfield/native_textfield_views.cc b/ui/views/controls/textfield/native_textfield_views.cc
index 749de28a8c69b629ccf854184d66e767855c1f0c..b9d18466c3c98acbaf276de2224d02feb31aea23 100644
--- a/ui/views/controls/textfield/native_textfield_views.cc
+++ b/ui/views/controls/textfield/native_textfield_views.cc
@@ -51,6 +51,11 @@
 #include "base/win/win_util.h"
 #endif
 
+#if defined(OS_WIN)
+#include "ui/base/win/accessibility_misc_utils.h"
+#include "ui/views/win/hwnd_util.h"
+#endif
+
 namespace {
 
 void ConvertRectToScreen(const views::View* src, gfx::Rect* r) {
@@ -696,6 +701,9 @@ void NativeTextfieldViews::HandleBlur() {
     is_cursor_visible_ = false;
     RepaintCursor();
   }
+#if defined(OS_WIN)
+  DestroyCaret();
+#endif
 
   touch_selection_controller_.reset();
 }
@@ -1372,6 +1380,20 @@ void NativeTextfieldViews::OnCaretBoundsChanged() {
   // Notify selection controller
   if (touch_selection_controller_.get())
     touch_selection_controller_->SelectionChanged();
+
+#if defined(OS_WIN)
+  // Move an invisible system caret to this location for accessibility.
+  if (GetRenderText()->focused() &&
+      !model_->HasSelection() &&

[sky, 2013/11/07 01:34:42]

How come you don't do this when there is a selection? Isn't there still a caret
at one end of the selection? And similarly if the drop cursor is visible are you
sure you don't want to update the caret to that position?

[dmazzoni, 2013/11/07 20:07:14]

You're right - I thought we didn't need to update it because it wasn't visible,
but it looks like accessibility apps track the caret even when it's at one end
of a selection. Done.
I still lean towards no, it's a placeholder and not the real caret - and I don't
think it'd be an accessibility issue since it'd always be right under the mouse
cursor.

+      !is_drop_cursor_visible_) {
+    gfx::Rect caret_rect(GetRenderText()->GetUpdatedCursorBounds());
+    caret_rect = ConvertRectToWidget(caret_rect);
+    caret_rect += GetWidget()->GetClientAreaBoundsInScreen().OffsetFromOrigin();
+    base::win::SetInvisibleSystemCaretRect(HWNDForView(this), caret_rect);
+  } else {
+    DestroyCaret();
+  }
+#endif
 }
 
 void NativeTextfieldViews::OnBeforeUserAction() {