Update touch selection to only modify one selection point at a time.

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index e7336e28507d7b642b2e5d92abf23f454822a89b..a547dbf1645ed4e0f8fc78d28a2c0bcaef0e0441 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1140,11 +1140,17 @@ void RenderWidgetHostViewAndroid::MoveCaret(const gfx::PointF& position) {
   MoveCaret(gfx::Point(position.x(), position.y()));
 }
 
+void RenderWidgetHostViewAndroid::MoveRangeSelectionExtent(
+    const gfx::PointF& position) {
+  DCHECK(content_view_core_);
+  content_view_core_->MoveRangeSelectionExtent(position);
+}
+
 void RenderWidgetHostViewAndroid::SelectBetweenCoordinates(
-    const gfx::PointF& start,
-    const gfx::PointF& end) {
+    const gfx::PointF& base,
+    const gfx::PointF& extent) {
   DCHECK(content_view_core_);
-  content_view_core_->SelectBetweenCoordinates(start, end);
+  content_view_core_->SelectBetweenCoordinates(base, extent);
 }
 
 void RenderWidgetHostViewAndroid::OnSelectionEvent(