Reland: ash: reset color management when new screens are hotplugged

ash/display/display_color_manager_chromeos.cc

Index: ash/display/display_color_manager_chromeos.cc
diff --git a/ash/display/display_color_manager_chromeos.cc b/ash/display/display_color_manager_chromeos.cc
index 0f382548f312abec881ad52ecf443eecfce9be27..5265b7824c1d1b15e46cbae3c3cc1108c0940930 100644
--- a/ash/display/display_color_manager_chromeos.cc
+++ b/ash/display/display_color_manager_chromeos.cc
@@ -164,6 +164,11 @@ DisplayColorManager::~DisplayColorManager() {
 void DisplayColorManager::OnDisplayModeChanged(
     const ui::DisplayConfigurator::DisplayStateList& display_states) {
   for (const ui::DisplaySnapshot* state : display_states) {
+    // Ensure we always reset the configuration before setting a new one.
+    configurator_->SetColorCorrection(
+        state->display_id(), std::vector<ui::GammaRampRGBEntry>(),
+        std::vector<ui::GammaRampRGBEntry>(), std::vector<float>());

[oshima, 2016/04/27 19:37:44]

Since DisplayConfigurator calls OndisplayModeChanged, isn't it better for
DisplayConfigurator to reset this before calling this?

[llandwerlin-old, 2016/04/28 10:41:52]

It seems DisplayConfigurator doesn't make any decision on the color correction,
it just forwards requests from callers.
Would you prefer this be in DisplayConfigurator?

[oshima, 2016/04/28 18:11:59]

Hm, that probably makes sense. lgtm

+
     if (calibration_map_[state->product_id()]) {
       ApplyDisplayColorCalibration(state->display_id(), state->product_id());
     } else {