Replace GR_MAC_BUILD by SK_BUILD_FOR_MAC.

Makefile.old

 # Simple makefile for skia library and test apps
 #
 # This is the handmade Makefile that we *used* to use before changing over
 # to gyp.  Keeping it around for now in case some folks need to use it...
 # but please contact epoger@google.com about anything you're still using in
 # here, so we can provide equivalent functionality in the gyp build.
 
 # setup our defaults
 CC := gcc
 GPP := g++
@@ skipping 114 matching lines @@
         SRC_LIST += src/images/SkScaledBitmapSampler.cpp
         
         ifeq ($(SKIA_MESA),true)
                 SRC_LIST += gpu/src/mesa/GrGLDefaultInterface_mesa.cpp
         else
                 SRC_LIST += gpu/src/mac/GrGLDefaultInterface_mac.cpp
         endif
         
 else
         LINKER_OPTS += -lpng -lfreetype -lrt
-        DEFINES += -DSK_BUILD_FOR_UNIX -DSK_ENABLE_LIBPNG -DGR_LINUX_BUILD=1
+        DEFINES += -DSK_BUILD_FOR_UNIX -DSK_ENABLE_LIBPNG
         ifeq ($(SKIA_MESA),true)
                 LINKER_OPTS += -lOSMesa -lGLU
                 DEFINES += -DSK_MESA
         else
                 LINKER_OPTS += -lGL -lGLU -lX11
         endif
 
         #Assume the color order for now.
         DEFINES += -DSK_SAMPLES_FOR_X
 
@@ skipping 172 matching lines @@
         @echo "    clean: removes entire out/ directory"
         @echo "    help: this text"
         @echo "Options: (after make, or in bash shell)"
         @echo "    SKIA_DEBUG=true for debug build"
         @echo "    SKIA_SHARED=true for shared-object libskia build"
         @echo "    SKIA_SCALAR=fixed for fixed-point build"
         @echo "    SKIA_BUILD_FOR=mac for mac build (e.g. CG for image decoding)"
         @echo "    SKIA_PDF_SUPPORT=false to disable the pdf generation backend"
         @echo "    SKIA_MESA=true to build with osmesa instead of native GL.
         @echo ""