Add support for multiple color modes

Bug: 29044347
Change-Id: Iea048eaa62f072a9bbefc4f3a6c29a9e593eab69
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 1a2a153..aa233df 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -149,6 +149,8 @@
     std::shared_ptr<const HWC2::Display::Config>
             getActiveConfig(int32_t displayId) const;
 
+    std::vector<int32_t> getColorModes(int32_t displayId) const;
+
     // for debugging ----------------------------------------------------------
     void dump(String8& out) const;