Make textures register with GrResourceCache2 as scratch.

include/gpu/GrResourceKey.h

Index: include/gpu/GrResourceKey.h
diff --git a/include/gpu/GrResourceKey.h b/include/gpu/GrResourceKey.h
new file mode 100644
index 0000000000000000000000000000000000000000..d3e82c8e580661709309a622b9cadfe887b56acf
--- /dev/null
+++ b/include/gpu/GrResourceKey.h
@@ -0,0 +1,113 @@
+
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrResourceKey_DEFINED
+#define GrResourceKey_DEFINED
+
+#include "GrTypes.h"
+#include "GrBinHashKey.h"
+
+class GrResourceKey {
+public:
+    static GrCacheID::Domain ScratchDomain() {
+        static const GrCacheID::Domain gDomain = GrCacheID::GenerateDomain();
+        return gDomain;
+    }
+
+    /** Uniquely identifies the GrGpuResource subclass in the key to avoid collisions
+        across resource types. */
+    typedef uint8_t ResourceType;
+
+    /** Flags set by the GrGpuResource subclass. */
+    typedef uint8_t ResourceFlags;
+
+    /** Generate a unique ResourceType */
+    static ResourceType GenerateResourceType();
+
+    /** Creates a key for resource */
+    GrResourceKey(const GrCacheID& id, ResourceType type, ResourceFlags flags) {
+        this->init(id.getDomain(), id.getKey(), type, flags);
+    };
+
+    GrResourceKey(const GrResourceKey& src) { fKey = src.fKey; }
+
+    GrResourceKey() { fKey.reset(); }
+
+    void reset(const GrCacheID& id, ResourceType type, ResourceFlags flags) {
+        this->init(id.getDomain(), id.getKey(), type, flags);
+    }
+
+    uint32_t getHash() const { return fKey.getHash(); }
+
+    bool isScratch() const {
+        return ScratchDomain() ==
+            *reinterpret_cast<const GrCacheID::Domain*>(fKey.getData() +
+                                                        kCacheIDDomainOffset);
+    }
+
+    ResourceType getResourceType() const {
+        return *reinterpret_cast<const ResourceType*>(fKey.getData() +
+                                                      kResourceTypeOffset);
+    }
+
+    ResourceFlags getResourceFlags() const {
+        return *reinterpret_cast<const ResourceFlags*>(fKey.getData() +
+                                                       kResourceFlagsOffset);
+    }
+
+    bool operator==(const GrResourceKey& other) const { return fKey == other.fKey; }
+
+    // A key indicating that the resource is not usable as a scratch resource.
+    static GrResourceKey& NullScratchKey() {
+        static const GrCacheID::Key kBogusKey = { { {0} } };
+        static GrCacheID kBogusID(ScratchDomain(), kBogusKey);
+        static GrResourceKey kNullScratchKey(kBogusID, NoneResourceType(), 0);
+        return kNullScratchKey;
+    }
+
+    bool isNullScratch() const {
+        return this->isScratch() && NoneResourceType() == this->getResourceType();
+    }
+
+private:
+    enum {
+        kCacheIDKeyOffset = 0,
+        kCacheIDDomainOffset = kCacheIDKeyOffset + sizeof(GrCacheID::Key),
+        kResourceTypeOffset = kCacheIDDomainOffset + sizeof(GrCacheID::Domain),
+        kResourceFlagsOffset = kResourceTypeOffset + sizeof(ResourceType),
+        kPadOffset = kResourceFlagsOffset + sizeof(ResourceFlags),
+        kKeySize = SkAlign4(kPadOffset),
+        kPadSize = kKeySize - kPadOffset
+    };
+
+    static ResourceType NoneResourceType() {
+        static const ResourceType gNoneResourceType = GenerateResourceType();
+        return gNoneResourceType;
+    }
+
+    void init(const GrCacheID::Domain domain,
+              const GrCacheID::Key& key,
+              ResourceType type,
+              ResourceFlags flags) {
+        union {
+            uint8_t  fKey8[kKeySize];
+            uint32_t fKey32[kKeySize / 4];
+        } keyData;
+
+        uint8_t* k = keyData.fKey8;
+        memcpy(k + kCacheIDKeyOffset, key.fData8, sizeof(GrCacheID::Key));
+        memcpy(k + kCacheIDDomainOffset, &domain, sizeof(GrCacheID::Domain));
+        memcpy(k + kResourceTypeOffset, &type, sizeof(ResourceType));
+        memcpy(k + kResourceFlagsOffset, &flags, sizeof(ResourceFlags));
+        memset(k + kPadOffset, 0, kPadSize);
+        fKey.setKeyData(keyData.fKey32);
+    }
+    GrBinHashKey<kKeySize> fKey;
+};
+
+#endif