Port FuzzPathop from chromium

fuzz/Fuzz.h

Index: fuzz/Fuzz.h
diff --git a/fuzz/Fuzz.h b/fuzz/Fuzz.h
index 07c2c8456e248cc35ec7f65d1dd8f19f64d007ab..79bf675f45ae15dde6121191ca53bb0694b9c941 100644
--- a/fuzz/Fuzz.h
+++ b/fuzz/Fuzz.h
@@ -16,6 +16,14 @@ class Fuzz : SkNoncopyable {
 public:
     explicit Fuzz(SkData*);
 
+    // Returns the total number of "random" bytes available.
+    size_t size();
+    // Returns the total number of "random" bytes remaining for randomness.
+    size_t remaining();
+
+    template <typename T>
+    bool next(T* n);
+
     bool nextBool();
     uint8_t  nextB();
     uint32_t nextU();
@@ -43,6 +51,17 @@ private:
     int fNextByte;
 };
 
+template <typename T>
+bool Fuzz::next(T* n) {
+    if (fNextByte + sizeof(T) > fBytes->size()) {
+        return false;
+    }
+
+    memcpy(n, fBytes->bytes() + fNextByte, sizeof(T));
+    fNextByte += sizeof(T);
+    return true;
+}
+
 struct Fuzzable {
     const char* name;
     void (*fn)(Fuzz*);