Makes ambient eq only affect internal display

This change modifieds the behavior of night_light_controller.cc to
selectively apply ambient color to only internal displays.

It also restructures night_light_controller_unittest.cc to allow for
multiple displays in AmbientEQTest.

The two tests affected by this change are also moved from
NightLightTest into AmbientEQTest.

Bug: 1078901
Change-Id: Ie967698d99713026591b44ddeaee294f80e2df60
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2453904
Commit-Queue: Nick Czajka <czajka@google.com>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816310}

ash/system/night_light/night_light_controller_impl.cc

@@ -170,12 +170,13 @@ int GetTemperatureRange(float temperature) {
 
 // Returns the color matrix that corresponds to the given |temperature|.
 // The matrix will be affected by the current |ambient_temperature_| if
-// GetAmbientColorEnabled() returns true.
+// |apply_ambient_temperature| is true.
 // If |in_linear_gamma_space| is true, the generated matrix is the one that
 // should be applied after gamma correction, and it corresponds to the
 // non-linear temperature value for the given |temperature|.
 SkMatrix44 MatrixFromTemperature(float temperature,
-                                 bool in_linear_gamma_space) {
+                                 bool in_linear_gamma_space,
+                                 bool apply_ambient_temperature) {
   if (in_linear_gamma_space)
     temperature =
         NightLightControllerImpl::GetNonLinearTemperature(temperature);
@@ -194,7 +195,7 @@ SkMatrix44 MatrixFromTemperature(float temperature,
 
   auto* night_light_controller = Shell::Get()->night_light_controller();
   DCHECK(night_light_controller);
-  if (night_light_controller->GetAmbientColorEnabled()) {
+  if (apply_ambient_temperature) {
     const gfx::Vector3dF& ambient_rgb_scaling_factors =
         night_light_controller->ambient_rgb_scaling_factors();
 
@@ -265,10 +266,18 @@ void ApplyTemperatureToHost(aura::WindowTreeHost* host, float temperature) {
     return;
   }
 
+  auto* night_light_controller = Shell::Get()->night_light_controller();
+  DCHECK(night_light_controller);
+
+  // Only apply ambient EQ to internal displays.
+  const bool apply_ambient_temperature =
+      night_light_controller->GetAmbientColorEnabled() &&
+      display::Display::IsInternalDisplayId(display_id);
+
   const SkMatrix44 linear_gamma_space_matrix =
-      MatrixFromTemperature(temperature, true);
+      MatrixFromTemperature(temperature, true, apply_ambient_temperature);
   const SkMatrix44 gamma_compressed_matrix =
-      MatrixFromTemperature(temperature, false);
+      MatrixFromTemperature(temperature, false, apply_ambient_temperature);
   const bool crtc_result = AttemptSettingHardwareCtm(
       display_id, linear_gamma_space_matrix, gamma_compressed_matrix);
   UpdateCompositorMatrix(host, gamma_compressed_matrix, crtc_result);
@@ -280,10 +289,6 @@ void ApplyTemperatureToHost(aura::WindowTreeHost* host, float temperature) {
 // by the current |ambient_temperature_| if GetAmbientColorEnabled() returns
 // true.
 void ApplyTemperatureToAllDisplays(float temperature) {
-  const SkMatrix44 linear_gamma_space_matrix =
-      MatrixFromTemperature(temperature, true);
-  const SkMatrix44 gamma_compressed_matrix =
-      MatrixFromTemperature(temperature, false);
 
   Shell* shell = Shell::Get();
   WindowTreeHostManager* wth_manager = shell->window_tree_host_manager();
@@ -291,9 +296,6 @@ void ApplyTemperatureToAllDisplays(float temperature) {
        shell->display_manager()->GetCurrentDisplayIdList()) {
     DCHECK_NE(display_id, display::kUnifiedDisplayId);
 
-    const bool crtc_result = AttemptSettingHardwareCtm(
-        display_id, linear_gamma_space_matrix, gamma_compressed_matrix);
-
     aura::Window* root_window =
         wth_manager->GetRootWindowForDisplayId(display_id);
     if (!root_window) {
@@ -305,7 +307,7 @@ void ApplyTemperatureToAllDisplays(float temperature) {
 
     auto* host = root_window->GetHost();
     DCHECK(host);
-    UpdateCompositorMatrix(host, gamma_compressed_matrix, crtc_result);
+    ApplyTemperatureToHost(host, temperature);
   }
 }