Switch several enums to enum classes

Change-Id: I00ecd0b61657196b51704f70ca31a9d1c1ac254e
diff --git a/libs/hwui/Caches.cpp b/libs/hwui/Caches.cpp
index f663f07..ff71313 100644
--- a/libs/hwui/Caches.cpp
+++ b/libs/hwui/Caches.cpp
@@ -245,7 +245,7 @@
     FLUSH_LOGD("Flushing caches (mode %d)", mode);
 
     switch (mode) {
-        case kFlushMode_Full:
+        case FlushMode::Full:
             textureCache.clear();
             patchCache.clear();
             dropShadowCache.clear();
@@ -254,13 +254,13 @@
             fboCache.clear();
             dither.clear();
             // fall through
-        case kFlushMode_Moderate:
+        case FlushMode::Moderate:
             fontRenderer->flush();
             textureCache.flush();
             pathCache.clear();
             tessellationCache.clear();
             // fall through
-        case kFlushMode_Layers:
+        case FlushMode::Layers:
             layerCache.clear();
             renderBufferCache.clear();
             break;