Convert from DIP to screen pixels for caret bounds

When the caret bounds are updated in RenderWidgetHostViewAura,
we need to convert from DIP to screen pixels, just like in
HWNDMessageHandler.

TBR=kenrb@chromium.org

Bug: 812892
Change-Id: I0797c5b2ed85349b85d90ac3fe5b2e4f21775fe0
Reviewed-on: https://chromium-review.googlesource.com/956540
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542187}

content/browser/renderer_host/render_widget_host_view_aura.cc

@@ -2372,7 +2372,10 @@ void RenderWidgetHostViewAura::OnSelectionBoundsChanged(
   const gfx::Rect caret_rect = ConvertRectToScreen(gfx::Rect(
       region->focus.edge_top_rounded().x(),
       region->focus.edge_top_rounded().y(), 1, region->focus.GetHeight()));
-  legacy_render_widget_host_HWND_->MoveCaretTo(caret_rect);
+  gfx::Rect dip_caret_rect = display::win::ScreenWin::DIPToScreenRect(
+      legacy_render_widget_host_HWND_->hwnd(), caret_rect);
+  dip_caret_rect.set_width(1);  // Collapse any selection.
+  legacy_render_widget_host_HWND_->MoveCaretTo(dip_caret_rect);
 #endif  // defined(OS_WIN)
 }