RenderTextHarfBuzz: Add support for multi line text selection.

ui/views/selection_controller.cc

Index: ui/views/selection_controller.cc
diff --git a/ui/views/selection_controller.cc b/ui/views/selection_controller.cc
index 38ba6ed0a842bd6379753f00bac3ced72c3dae42..ac3c61cf01213f890bbe61984dad8dc2e4df7abb 100644
--- a/ui/views/selection_controller.cc
+++ b/ui/views/selection_controller.cc
@@ -181,18 +181,7 @@ void SelectionController::SelectThroughLastDragLocation() {
 
   delegate_->OnBeforePointerAction();
 
-  // TODO(karandeepb): See if this can be handled at the RenderText level.
-  const bool drags_to_end = PlatformStyle::kTextDragVerticallyDragsToEnd;
-  if (drags_to_end && last_drag_location_.y() < 0) {
-    render_text->MoveCursor(gfx::LINE_BREAK, gfx::CURSOR_LEFT,
-                            gfx::SELECTION_RETAIN);
-  } else if (drags_to_end &&
-             last_drag_location_.y() > delegate_->GetViewHeight()) {
-    render_text->MoveCursor(gfx::LINE_BREAK, gfx::CURSOR_RIGHT,
-                            gfx::SELECTION_RETAIN);
-  } else {
-    render_text->MoveCursorTo(last_drag_location_, true);
-  }
+  render_text->MoveCursorTo(last_drag_location_, true);
 
   if (aggregated_clicks_ == 1) {
     render_text->SelectWord();