Only build stats library if examples are enabled.

Change-Id: Iad4e8b88dbc669d008e6dfb98ac5926de065c44a
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8f209ae..a58e54f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -223,7 +223,10 @@
 add_library(aom_rtcd OBJECT ${AOM_RTCD_SOURCES})
 add_dependencies(aom_rtcd aom_version)
 
-add_library(aom_encoder_stats OBJECT ${AOM_ENCODER_STATS_SOURCES})
+if(ENABLE_EXAMPLES)
+  add_library(aom_encoder_stats OBJECT ${AOM_ENCODER_STATS_SOURCES})
+  set(AOM_LIB_TARGETS ${AOM_LIB_TARGETS} aom_encoder_stats)
+endif()
 add_library(aom ${AOM_SOURCES} $<TARGET_OBJECTS:aom_rtcd>)
 
 if(NOT MSVC AND NOT APPLE)