gsk: Add a debug flag for transforms

gsk/gskdebug.c

@@ -7,6 +7,7 @@ static const GDebugKey gsk_debug_keys[] = {
   { "cairo", GSK_DEBUG_CAIRO },
   { "opengl", GSK_DEBUG_OPENGL },
   { "shaders", GSK_DEBUG_SHADERS },
+  { "transforms", GSK_DEBUG_TRANSFORMS }
 };
 #endif
 

gsk/gskdebugprivate.h

@@ -10,7 +10,8 @@ typedef enum {
   GSK_DEBUG_RENDERER    = 1 << 1,
   GSK_DEBUG_CAIRO       = 1 << 2,
   GSK_DEBUG_OPENGL      = 1 << 3,
-  GSK_DEBUG_SHADERS     = 1 << 4
+  GSK_DEBUG_SHADERS     = 1 << 4,
+  GSK_DEBUG_TRANSFORMS  = 1 << 5
 } GskDebugFlags;
 
 typedef enum {