[Night Light] Backend ui::Layer work

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index 57fd1ccf340ca04d0b163d3707c027bb14575e46..64faa6a1418a7f56175b47817e0a521397ef6afe 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -97,6 +97,9 @@ Layer::Layer()
       layer_brightness_(0.0f),
       layer_grayscale_(0.0f),
       layer_inverted_(false),
+      layer_temperature_(0.0f),
+      layer_blue_scale_(1.0f),
+      layer_green_scale_(1.0f),
       layer_mask_(NULL),
       layer_mask_back_link_(NULL),
       zoom_(1),
@@ -120,6 +123,9 @@ Layer::Layer(LayerType type)
       layer_brightness_(0.0f),
       layer_grayscale_(0.0f),
       layer_inverted_(false),
+      layer_temperature_(0.0f),
+      layer_blue_scale_(1.0f),
+      layer_green_scale_(1.0f),
       layer_mask_(NULL),
       layer_mask_back_link_(NULL),
       zoom_(1),
@@ -372,6 +378,10 @@ float Layer::GetCombinedOpacity() const {
   return opacity;
 }
 
+void Layer::SetLayerTemperature(float value) {
+  GetAnimator()->SetTemperature(value);
+}
+
 void Layer::SetBackgroundBlur(int blur_radius) {
   background_blur_radius_ = blur_radius;
 
@@ -458,6 +468,15 @@ void Layer::SetLayerFilters() {
     filters.Append(cc::FilterOperation::CreateGrayscaleFilter(
         layer_grayscale_));
   }
+  if (layer_temperature_) {
+    float color_matrix[] = {
+        1.0f,               0.0f,              0.0f, 0.0f, 0.0f,
+        0.0f, layer_green_scale_,              0.0f, 0.0f, 0.0f,
+        0.0f,               0.0f, layer_blue_scale_, 0.0f, 0.0f,
+        0.0f,               0.0f,              0.0f, 1.0f, 0.0f
+    };
+    filters.Append(cc::FilterOperation::CreateColorMatrixFilter(color_matrix));
+  }
   if (layer_inverted_)
     filters.Append(cc::FilterOperation::CreateInvertFilter(1.0));
   // Brightness goes last, because the resulting colors neeed clamping, which
@@ -1054,6 +1073,17 @@ void Layer::SetColorFromAnimation(SkColor color) {
   SetFillsBoundsOpaquely(SkColorGetA(color) == 0xFF);
 }
 
+void Layer::SetTemperatureFromAnimation(float temperature) {
+  layer_temperature_ = temperature;
+
+  // If we only tone down the blue scale, the screen will look very green so we
+  // also need to tone down the green, but with a less value compared to the
+  // blue scale to avoid making things look very red.
+  layer_blue_scale_ = 1.0f - temperature;
+  layer_green_scale_ = 1.0f - 0.3f * temperature;
+  SetLayerFilters();
+}
+
 void Layer::ScheduleDrawForAnimation() {
   ScheduleDraw();
 }
@@ -1090,6 +1120,10 @@ SkColor Layer::GetColorForAnimation() const {
       solid_color_layer_->background_color() : SK_ColorBLACK;
 }
 
+float Layer::GetTemperatureFromAnimation() const {
+  return layer_temperature_;
+}
+
 float Layer::GetDeviceScaleFactor() const {
   return device_scale_factor_;
 }