share constructors/enum in both variants of SkReadBuffer

Bug: skia:
Change-Id: I5a90e1f9a9687df2dd2f69d96ac805bf244cec50
Reviewed-on: https://skia-review.googlesource.com/c/179844
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
Auto-Submit: Mike Reed <reed@google.com>
diff --git a/src/core/SkReadBuffer.h b/src/core/SkReadBuffer.h
index bbb036f..83b684c 100644
--- a/src/core/SkReadBuffer.h
+++ b/src/core/SkReadBuffer.h
@@ -25,8 +25,6 @@
 class SkData;
 class SkImage;
 
-#ifndef SK_DISABLE_READBUFFER
-
 class SkReadBuffer {
 public:
     SkReadBuffer();
@@ -47,6 +45,8 @@
         kSerializeFonts_Version            = 67,
     };
 
+#ifndef SK_DISABLE_READBUFFER
+
     /**
      *  Returns true IFF the version is older than the specified version.
      */
@@ -227,30 +227,9 @@
     }
 
     bool fError = false;
-};
 
 #else // #ifndef SK_DISABLE_READBUFFER
 
-class SkReadBuffer {
-public:
-    SkReadBuffer() {}
-    SkReadBuffer(const void*, size_t) {}
-
-    enum Version {
-        kTileModeInBlurImageFilter_Version = 56,
-        kTileInfoInSweepGradient_Version   = 57,
-        k2PtConicalNoFlip_Version          = 58,
-        kRemovePictureImageFilterLocalSpace = 59,
-        kRemoveHeaderFlags_Version         = 60,
-        kTwoColorDrawShadow_Version        = 61,
-        kDontNegateImageSize_Version       = 62,
-        kStoreImageBounds_Version          = 63,
-        kRemoveOccluderFromBlurMaskFilter  = 64,
-        kFloat4PaintColor_Version          = 65,
-        kSaveBehind_Version                = 66,
-        kSerializeFonts_Version            = 67,
-    };
-
     bool isVersionLT(Version) const { return false; }
     uint32_t getVersion() const { return 0xffffffff; }
     void     setVersion(int) {}
@@ -332,8 +311,7 @@
         static const SkDeserialProcs procs;
         return procs;
     }
+#endif
 };
 
-#endif // #ifndef SK_DISABLE_READBUFFER
-
 #endif // SkReadBuffer_DEFINED