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 dac44e1453d9c590b5d3068b167c7379a05449c0..3a2dc883f4031ea824c2b2088f2d1ecfceae9ecb 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -1160,11 +1160,17 @@ void RenderWidgetHostViewAndroid::MoveCaret(const gfx::PointF& position) {
   MoveCaret(gfx::Point(position.x(), position.y()));
 }
 
+void RenderWidgetHostViewAndroid::MoveRangeSelectionExtent(
+    const gfx::PointF& extent) {
+  DCHECK(content_view_core_);
+  content_view_core_->MoveRangeSelectionExtent(extent);
+}
+
 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(