Remove GrRefCnt.h in favor of SkRefCnt.h

This removes GrRefCnt.h with all its tyepdefs and #defines and just switch them
to the Sk* equivalents.

GrSafeSetNull was promoted to SkSafeSetNull in SkRefCnt.h.

BUG=None
TEST=none, no functional changes.
R=bsalomon@google.com, robertphillips@google.com

Author: tfarina@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23904003

git-svn-id: http://skia.googlecode.com/svn/trunk@11151 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index 5145b29..d931de5 100644
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -167,8 +167,8 @@
     fOvalRenderer->unref();
 
     fGpu->unref();
-    GrSafeUnref(fPathRendererChain);
-    GrSafeUnref(fSoftwarePathRenderer);
+    SkSafeUnref(fPathRendererChain);
+    SkSafeUnref(fSoftwarePathRenderer);
     fDrawState->unref();
 
     --THREAD_INSTANCE_COUNT;
@@ -186,8 +186,8 @@
 
     // a path renderer may be holding onto resources that
     // are now unusable
-    GrSafeSetNull(fPathRendererChain);
-    GrSafeSetNull(fSoftwarePathRenderer);
+    SkSafeSetNull(fPathRendererChain);
+    SkSafeSetNull(fSoftwarePathRenderer);
 
     delete fDrawBuffer;
     fDrawBuffer = NULL;
@@ -221,8 +221,8 @@
     fTextureCache->purgeAllUnlocked();
     fFontCache->freeAll();
     // a path renderer may be holding onto resources
-    GrSafeSetNull(fPathRendererChain);
-    GrSafeSetNull(fSoftwarePathRenderer);
+    SkSafeSetNull(fPathRendererChain);
+    SkSafeSetNull(fSoftwarePathRenderer);
 }
 
 size_t GrContext::getGpuTextureCacheBytes() const {