Make PageScaleFactor work for oopif subframes.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 4c82e7310c2eeba5d2815e484ca6c08fc2b32063..8869e8284efe595557d2d72328813fe12ae3d954 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -1257,9 +1257,16 @@ void PictureLayerImpl::UpdateIdealScales() {
                           ? layer_tree_impl()->current_page_scale_factor()
                           : 1.f;
   ideal_device_scale_ = layer_tree_impl()->device_scale_factor();
+  ideal_contents_scale_ = GetIdealContentsScale();
+  if (!layer_tree_impl()->PageScaleLayer()) {
+    float subframe_page_scale_factor =
+        layer_tree_impl()->GetSubframePageScaleFactor();
+    ideal_page_scale_ = subframe_page_scale_factor;
+    ideal_contents_scale_ *= subframe_page_scale_factor;
+  }
   ideal_contents_scale_ =
       std::min(kMaxIdealContentsScale,
-               std::max(GetIdealContentsScale(), min_contents_scale));
+               std::max(ideal_contents_scale_, min_contents_scale));
   ideal_source_scale_ =
       ideal_contents_scale_ / ideal_page_scale_ / ideal_device_scale_;
   UMA_HISTOGRAM_CUSTOM_COUNTS("Renderer4.IdealContentsScale",