Add specialized content key class for resources.

src/gpu/GrPath.cpp

Index: src/gpu/GrPath.cpp
diff --git a/src/gpu/GrPath.cpp b/src/gpu/GrPath.cpp
index eb956fbf658e77574dec939d65f198e61ce90f21..a989be09676b01201ba9866e193be46c2082ef72 100644
--- a/src/gpu/GrPath.cpp
+++ b/src/gpu/GrPath.cpp
@@ -13,15 +13,17 @@ template<int NumBits> static uint64_t get_top_n_float_bits(float f) {
     return floatBits >> (32 - NumBits);
 }
 
-GrResourceKey GrPath::ComputeKey(const SkPath& path, const SkStrokeRec& stroke) {
-    static const GrCacheID::Domain gPathDomain = GrCacheID::GenerateDomain();
+void GrPath::ComputeKey(const SkPath& path, const SkStrokeRec& stroke, GrContentKey* key) {
+    static const GrContentKey::Domain kDomain = GrContentKey::GenerateDomain();
 
-    GrCacheID::Key key;
-    uint64_t* keyData = key.fData64;
-    keyData[0] = path.getGenerationID();
-    keyData[1] = ComputeStrokeKey(stroke);
-
-    return GrResourceKey(GrCacheID(gPathDomain, key), 0);
+    GrContentKey::Builder builder(key, kDomain, 3);
+    struct PathKey {
+        uint32_t fGenID;
+        uint64_t fStroke;
+    };
+    PathKey *pathKey = reinterpret_cast<PathKey*>(&builder[0]);
+    pathKey->fGenID = path.getGenerationID();
+    pathKey->fStroke = ComputeStrokeKey(stroke);
 }
 
 uint64_t GrPath::ComputeStrokeKey(const SkStrokeRec& stroke) {