Remove DeviceLightEvent implementation

content/test/layouttest_support.cc

Index: content/test/layouttest_support.cc
diff --git a/content/test/layouttest_support.cc b/content/test/layouttest_support.cc
index 5b003d70d881f223608096af7bd06d6f720fc581..74071e642e78f8924e747efcdd7e45ed35e24306 100644
--- a/content/test/layouttest_support.cc
+++ b/content/test/layouttest_support.cc
@@ -269,10 +269,6 @@ void SetMockGamepadProvider(std::unique_ptr<RendererGamepadProvider> provider) {
                                            std::move(provider));
 }
 
-void SetMockDeviceLightData(const double data) {
-  RendererBlinkPlatformImpl::SetMockDeviceLightDataForTesting(data);
-}
-
 void SetMockDeviceMotionData(const MotionData& data) {
   RendererBlinkPlatformImpl::SetMockDeviceMotionDataForTesting(data);
 }