Properly scale the coordinate for TouchSelection when use-zoom-for-dsf mode is on.

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 14630239844e4b9f71efaac400da93aa5de1fd74..175244d66963085033a7a30dd7c7040b8d39afa8 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -7968,7 +7968,23 @@ TEST_F(LayerTreeHostImplTest, LatencyInfoPassedToCompositorFrameMetadata) {
       ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT, 0, NULL));
 }
 
-TEST_F(LayerTreeHostImplTest, SelectionBoundsPassedToCompositorFrameMetadata) {
+class LayerTreeHostImplTestWithPaintedDeviceScaleFactor
+    : public LayerTreeHostImplTest,
+      public testing::WithParamInterface<float> {
+ public:
+  LayerTreeHostImplTestWithPaintedDeviceScaleFactor() = default;
+  ~LayerTreeHostImplTestWithPaintedDeviceScaleFactor() override = default;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImplTestWithPaintedDeviceScaleFactor);
+};
+
+TEST_P(LayerTreeHostImplTestWithPaintedDeviceScaleFactor,
+       SelectionBoundsPassedToCompositorFrameMetadata) {
+  float painted_device_scale = GetParam();
+  host_impl_->active_tree()->set_painted_device_scale_factor(
+      painted_device_scale);
+
   int root_layer_id = 1;
   scoped_ptr<SolidColorLayerImpl> root =
       SolidColorLayerImpl::Create(host_impl_->active_tree(), root_layer_id);
@@ -8013,12 +8029,20 @@ TEST_F(LayerTreeHostImplTest, SelectionBoundsPassedToCompositorFrameMetadata) {
       fake_output_surface->last_sent_frame().metadata.selection;
   EXPECT_EQ(selection.start.type, selection_after.start.type);
   EXPECT_EQ(selection.end.type, selection_after.end.type);
-  EXPECT_EQ(gfx::PointF(selection_bottom), selection_after.start.edge_bottom);
-  EXPECT_EQ(gfx::PointF(selection_top), selection_after.start.edge_top);
+  EXPECT_EQ(gfx::ScalePoint(gfx::PointF(selection_bottom),

[danakj, 2016/02/25 19:37:22]

Does this all mean that there is some input to the compositor that isn't being
scaled by the painted device scale factor?

I'm not expecting cc to have to use the painted DSF for anything other than
passing it along. So I'd expect all inputs to already be scaled.

[oshima, 2016/02/25 21:52:03]

This is an output from compositor. Currently, cc/ is responsible for computing
the selection bounds, which is attached to the frame metadata, which in turn, is
consumed by browser process in DIP.  See ComputeViewportSelectionBound (It
converts from layer -> screen -> dip).

Other selection code lives in content/renderer so it's not clear to me why this
is in cc/ though.

While it's technically possible to move the conversion to browser process, but
I'd like to avoid it because browser currently expects to receive DIP from
renderer process.

+                            1.f / painted_device_scale),
+            selection_after.start.edge_bottom);
+  EXPECT_EQ(
+      gfx::ScalePoint(gfx::PointF(selection_top), 1.f / painted_device_scale),
+      selection_after.start.edge_top);
   EXPECT_TRUE(selection_after.start.visible);
   EXPECT_TRUE(selection_after.start.visible);
 }
 
+INSTANTIATE_TEST_CASE_P(WithPaintedDeviceScaleFactor,
+                        LayerTreeHostImplTestWithPaintedDeviceScaleFactor,
+                        testing::Values(1.0f, 1.5f, 2.0f));
+
 class SimpleSwapPromiseMonitor : public SwapPromiseMonitor {
  public:
   SimpleSwapPromiseMonitor(LayerTreeHost* layer_tree_host,