ui/ozone/drm_display: Crank up SDR brightness to 85%

This CL increases the SDR luminance (on HDR-capable systems and
with an HDR-capable display) to 85%, following instructions from
the PM office amd also to line up with Apple's maximum SDR value
(equivalenty, HDR headroom) when brightness is at the max.

Bug: b:165824699
Change-Id: I1bbfbba3512d87f84c26e5acc71cfd8f59a07e48
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2367872
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Auto-Submit: Miguel Casas <mcasas@chromium.org>
Reviewed-by: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800620}

ui/ozone/platform/drm/gpu/drm_display.cc

@@ -276,7 +276,8 @@ void DrmDisplay::SetColorSpace(const gfx::ColorSpace& color_space) {
 
   // TODO(mcasas) This should be the inverse value of DisplayChangeObservers's
   // FillDisplayColorSpaces's kHDRLevel, move to a common place.
-  constexpr float kSDRLevel = 0.75;
+  // TODO(b/165822222): adjust this level based on the display brightness.
+  constexpr float kSDRLevel = 0.85;
   // TODO(mcasas): Retrieve this from the |drm_| HardwareDisplayPlaneManager.
   constexpr size_t kNumGammaSamples = 64ul;
   // Only using kSDRLevel of the available values shifts the contrast ratio, we

ui/ozone/platform/drm/gpu/drm_display_unittest.cc

@@ -149,7 +149,7 @@ TEST_F(DrmDisplayTest, SetColorSpace) {
   drm_display_.SetColorSpace(kHDRColorSpace);
 
   const auto kSDRColorSpace = gfx::ColorSpace::CreateREC709();
-  constexpr float kSDRLevel = 0.75;
+  constexpr float kSDRLevel = 0.85;
   constexpr float kExponent = 1.2;
   EXPECT_CALL(*plane_manager,
               SetGammaCorrection(_, SizeIs(0),
@@ -177,7 +177,7 @@ TEST_F(DrmDisplayTest, SetEmptyGammaCorrectionHDRDisplay) {
   ON_CALL(*plane_manager, SetGammaCorrection(_, _, _))
       .WillByDefault(::testing::Return(true));
 
-  constexpr float kSDRLevel = 0.75;
+  constexpr float kSDRLevel = 0.85;
   constexpr float kExponent = 1.2;
   EXPECT_CALL(*plane_manager,
               SetGammaCorrection(_, SizeIs(0),