Add some of my favorite headers.

gyp/core.gypi

Index: gyp/core.gypi
diff --git a/gyp/core.gypi b/gyp/core.gypi
index 94711b9a3dd49c07d990eb26a009ae07eea36f69..ea3a49349d19026f355f9125322b1956625376a4 100644
--- a/gyp/core.gypi
+++ b/gyp/core.gypi
@@ -344,13 +344,25 @@
 
         # private
         '<(skia_include_path)/private/SkAtomics.h',
+        '<(skia_include_path)/private/SkChecksum.h',
+        '<(skia_include_path)/private/SkFloatBits.h',
+        '<(skia_include_path)/private/SkFloatingPoint.h',
+        '<(skia_include_path)/private/SkFunction.h',
+        '<(skia_include_path)/private/SkGpuFenceSync.h',
+        '<(skia_include_path)/private/SkMiniRecorder.h',
         '<(skia_include_path)/private/SkMutex.h',
         '<(skia_include_path)/private/SkOnce.h',
         '<(skia_include_path)/private/SkOncePtr.h',
+        '<(skia_include_path)/private/SkRecords.h',
         '<(skia_include_path)/private/SkSemaphore.h',
         '<(skia_include_path)/private/SkSpinlock.h',
         '<(skia_include_path)/private/SkTemplates.h',
+        '<(skia_include_path)/private/SkTHash.h',
         '<(skia_include_path)/private/SkThreadID.h',
+        '<(skia_include_path)/private/SkTLogic.h',
+        '<(skia_include_path)/private/SkUniquePtr.h',
+        '<(skia_include_path)/private/SkUtility.h',
+        '<(skia_include_path)/private/SkWeakRefCnt.h',
 
         # Path ops
         '<(skia_include_path)/pathops/SkPathOps.h',