Make max number of vertex attributes be checked dynamically

src/gpu/GrPrimitiveProcessor.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrPrimitiveProcessor_DEFINED
 #define GrPrimitiveProcessor_DEFINED
 
@@ skipping 133 matching lines @@
  * GrPrimitiveProcessor defines an interface which all subclasses must implement.  All
  * GrPrimitiveProcessors must proivide seed color and coverage for the Ganesh color / coverage
  * pipelines, and they must provide some notion of equality
  */
 class GrPrimitiveProcessor : public GrProcessor {
 public:
     // Only the GrGeometryProcessor subclass actually has a geo shader or vertex attributes, but
     // we put these calls on the base class to prevent having to cast
     virtual bool willUseGeoShader() const = 0;
 
-    /*
-     * This is a safeguard to prevent GrPrimitiveProcessor's from going beyond platform specific
-     * attribute limits. This number can almost certainly be raised if required.
-     */
-    static const int kMaxVertexAttribs = 8;
-
     struct Attribute {
         Attribute()
             : fName(nullptr)
             , fType(kFloat_GrVertexAttribType)
             , fOffset(0) {}
         Attribute(const char* name, GrVertexAttribType type,
                   GrSLPrecision precision = kDefault_GrSLPrecision)
             : fName(name)
             , fType(type)
             , fOffset(SkAlign4(GrVertexAttribTypeSize(type)))
             , fPrecision(precision) {}
         const char* fName;
         GrVertexAttribType fType;
         size_t fOffset;
         GrSLPrecision fPrecision;
     };
 
-    int numAttribs() const { return fNumAttribs; }
-    const Attribute& getAttrib(int index) const {
-        SkASSERT(index < fNumAttribs);
-        return fAttribs[index];
-    }
+    int numAttribs() const { return fAttribs.count(); }
+    const Attribute& getAttrib(int index) const { return fAttribs[index]; }
 
     // Returns the vertex stride of the GP.  A common use case is to request geometry from a
     // drawtarget based off of the stride, and to populate this memory using an implicit array of
     // structs.  In this case, it is best to assert the vertexstride == sizeof(VertexStruct).
     size_t getVertexStride() const { return fVertexStride; }
 
     /**
      * Computes a transformKey from an array of coord transforms. Will only look at the first
      * <numCoords> transforms in the array.
      *
@@ skipping 28 matching lines @@
     virtual GrPixelLocalStorageState getPixelLocalStorageState() const { 
         return kDisabled_GrPixelLocalStorageState;
     }
 
     /**
      * If non-null, overrides the dest color returned by GrGLSLFragmentShaderBuilder::dstColor().
      */
     virtual const char* getDestColorOverride() const { return nullptr; }
     
 protected:
-    GrPrimitiveProcessor()
-        : fNumAttribs(0)
-        , fVertexStride(0) {}
+    GrPrimitiveProcessor() : fVertexStride(0) {}
 
-    Attribute fAttribs[kMaxVertexAttribs];
-    int fNumAttribs;
+    enum { kPreallocAttribCnt = 8 };
+    SkSTArray<kPreallocAttribCnt, Attribute> fAttribs;
     size_t fVertexStride;
 
 private:
     void notifyRefCntIsZero() const final {};
     virtual bool hasExplicitLocalCoords() const = 0;
 
     typedef GrProcessor INHERITED;
 };
 
 #endif