am c6f93a43: Merge "Add missing include to fix libc++ build."

* commit 'c6f93a43d636b0ad16b75adf664c6a33d30b39dd':
  Add missing include to fix libc++ build.
diff --git a/libs/gui/tests/SRGB_test.cpp b/libs/gui/tests/SRGB_test.cpp
index 2d5b8aa..da2add7 100644
--- a/libs/gui/tests/SRGB_test.cpp
+++ b/libs/gui/tests/SRGB_test.cpp
@@ -19,6 +19,8 @@
 
 #include "GLTest.h"
 
+#include <math.h>
+
 #include <gui/CpuConsumer.h>
 #include <gui/Surface.h>
 #include <gui/SurfaceComposerClient.h>