Centralize the predicate for a glyph being too large for the atlas

Centralize the calculation to SkGlyphCacheCommon. This allows this
function to be used with NO_GPU.

In addition, this was used in the last remaining function in GrTest.
That function was used in a single place. I made the function a static
and remove GrTest.h. This had massive knock-on effects.

Change-Id: I80f874a988f9af4383a83acf7c273d23b8d67c22
Reviewed-on: https://skia-review.googlesource.com/151480
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Herb Derby <herb@google.com>
diff --git a/gm/imagefromyuvtextures.cpp b/gm/imagefromyuvtextures.cpp
index 9d72cc0..7335f2e 100644
--- a/gm/imagefromyuvtextures.cpp
+++ b/gm/imagefromyuvtextures.cpp
@@ -9,10 +9,10 @@
 
 #include "gm.h"
 
+#include "GrBackendSurface.h"
 #include "GrContext.h"
 #include "GrContextPriv.h"
 #include "GrGpu.h"
-#include "GrTest.h"
 #include "SkBitmap.h"
 #include "SkGradientShader.h"
 #include "SkImage.h"