Add a GPU paths to resource cache of the context

src/gpu/GrPath.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrPath.h"
 
 SK_DEFINE_INST_COUNT(GrPath)
+
+GrResourceKey GrPath::ComputeKey(const SkPath& path, const SkStrokeRec& stroke) {
+    static const GrResourceKey::ResourceType gPathResourceType = GrResourceKey::GenerateResourceType();
+    static const GrCacheID::Domain gPathDomain = GrCacheID::GenerateDomain();
+
+    GrCacheID::Key key;
+    uint32_t* keyData = key.fData32;
+    keyData[0] = path.getGenerationID();
+
+    SK_COMPILE_ASSERT(SkPaint::kJoinCount <= 3, cap_shift_will_be_wrong);
+    keyData[1] = stroke.needToApply();
+    if (0 != keyData[1]) {
+        keyData[1] |= stroke.getJoin() << 1;
+        keyData[1] |= stroke.getCap() << 3;
+        keyData[2] = static_cast<uint32_t>(stroke.getMiter());
+        keyData[3] = static_cast<uint32_t>(stroke.getWidth());
+    } else {
+        keyData[2] = 0;
+        keyData[3] = 0;
+    }
+
+    return GrResourceKey(GrCacheID(gPathDomain, key), gPathResourceType, 0);
+}