Gradients are serialized (and can be constructed) as SkColor4f + SkColorSpace

src/core/SkReadBuffer.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkReadBuffer_DEFINED
 #define SkReadBuffer_DEFINED
 
@@ skipping 50 matching lines @@
         kDropShadowMode_Version            = 37,
         kPictureImageFilterResolution_Version = 38,
         kPictureImageFilterLevel_Version   = 39,
         kImageFilterNoUniqueID_Version     = 40,
         kBitmapSourceFilterQuality_Version = 41,
         kPictureShaderHasPictureBool_Version = 42,
         kHasDrawImageOpCodes_Version       = 43,
         kAnnotationsMovedToCanvas_Version  = 44,
         kLightingShaderWritesInvNormRotation = 45,
         kBlurMaskFilterWritesOccluder      = 47,
+        kGradientShaderFloatColor_Version  = 49,
     };
 
     /**
      *  Returns true IFF the version is older than the specified version.
      */
     bool isVersionLT(Version targetVersion) const {
         SkASSERT(targetVersion > 0);
         return fVersion > 0 && fVersion < targetVersion;
     }
 
@@ skipping 181 matching lines @@
 #ifdef DEBUG_NON_DETERMINISTIC_ASSERT
     // Debugging counter to keep track of how many bitmaps we
     // have decoded.
     int fDecodedBitmapIndex;
 #endif // DEBUG_NON_DETERMINISTIC_ASSERT
 
     SkInflator* fInflator = nullptr;
 };
 
 #endif // SkReadBuffer_DEFINED