Clean up physical coupling

Narrow the use of #include directives in hwui, replacing with forward
declarations where straightforward. Speeds compiles; doesn't do any
restructuring of code.

Change-Id: Icac2baffb5896f55d8c6718e9bd9d4bfa02d3ca0
diff --git a/libs/hwui/font/CachedGlyphInfo.h b/libs/hwui/font/CachedGlyphInfo.h
index 6680a00..0642d59 100644
--- a/libs/hwui/font/CachedGlyphInfo.h
+++ b/libs/hwui/font/CachedGlyphInfo.h
@@ -19,11 +19,11 @@
 
 #include <SkFixed.h>
 
-#include "CacheTexture.h"
-
 namespace android {
 namespace uirenderer {
 
+class CacheTexture;
+
 struct CachedGlyphInfo {
     // Has the cache been invalidated?
     bool mIsValid;