Added a class acting as a fake caret for accessibility.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 9c5ce2cd0dc3fec706c09019966b7989d2e25ec5..99129252a9068f36b7fbae015186d99fe7e8403e 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -63,6 +63,7 @@
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
 #include "third_party/WebKit/public/web/WebCompositionUnderline.h"
 #include "ui/accessibility/platform/aura_window_properties.h"
+#include "ui/accessibility/platform/ax_fake_caret_win.h"

[dmazzoni, 2017/03/28 15:41:21]

I think this needs to go in the #if defined(OS_WIN) block below

 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/cursor_client.h"
 #include "ui/aura/client/cursor_client_observer.h"
@@ -2338,7 +2339,6 @@ void RenderWidgetHostViewAura::OnSelectionBoundsChanged(
 void RenderWidgetHostViewAura::OnTextSelectionChanged(
     TextInputManager* text_input_manager,
     RenderWidgetHostViewBase* updated_view) {
-#if defined(USE_X11) && !defined(OS_CHROMEOS)
   if (!GetTextInputManager())
     return;
 
@@ -2355,6 +2355,7 @@ void RenderWidgetHostViewAura::OnTextSelectionChanged(
   if (!focused_view)
     return;
 
+#if defined(USE_X11) && !defined(OS_CHROMEOS)
   const TextInputManager::TextSelection* selection =
       GetTextInputManager()->GetTextSelection(focused_view);
   if (selection->selected_text().length()) {
@@ -2362,7 +2363,25 @@ void RenderWidgetHostViewAura::OnTextSelectionChanged(
     ui::ScopedClipboardWriter clipboard_writer(ui::CLIPBOARD_TYPE_SELECTION);
     clipboard_writer.WriteText(selection->selected_text());
   }
-#endif  // defined(USE_X11) && !defined(OS_CHROMEOS)
+
+// #endif defined(USE_X11) && !defined(OS_CHROMEOS)
+#elseif defined(OS_WIN)
+  // Some assistive software need to track the location of the caret.
+  if (!GetRenderWidgetHost() ||
+      !GetRenderWidgetHost()->GetRootBrowserAccessibilityManager())

[dmazzoni, 2017/03/28 15:41:21]

Would it be possible to make this code work without a
BrowserAccessibilityManager?

The Windows Magnifier can follow the caret without accessibility
being enabled otherwise, for example.

+    return;
+
+  // Not using |GetCaretBounds| because it includes the whole of the selection,
+  // not just the focus.
+  const TextInputManager::SelectionRegion* region =
+      GetTextInputManager()->GetSelectionRegion(focused_view);
+  if (!region)
+    return;
+  gfx::Rect caret_rect = ConvertRectToScreen(gfx::Rect(
+      region->focus.edge_top_rounded().x(),
+      region->focus.edge_top_rounded().y(), 1, region->focus.GetHeight()));
+  ui::AXFakeCaretWin::SetBounds(caret_rect);
+#endif  // defined(OS_WIN)
 }
 
 void RenderWidgetHostViewAura::SetPopupChild(