Shared image generator

src/core/SkImageCacherator.h

Index: src/core/SkImageCacherator.h
diff --git a/src/core/SkImageCacherator.h b/src/core/SkImageCacherator.h
index 2d9e94cc4d7f9bc7b1e3a439f69eebe3a636b800..cd5ac9ba09b6b6c0f9c0d8336cef88f0dad5fe83 100644
--- a/src/core/SkImageCacherator.h
+++ b/src/core/SkImageCacherator.h
@@ -9,7 +9,6 @@
 #define SkImageCacherator_DEFINED
 
 #include "SkImageGenerator.h"
-#include "SkMutex.h"
 #include "SkTemplates.h"
 
 class GrContext;
@@ -26,6 +25,8 @@ public:
     // Takes ownership of the generator
     static SkImageCacherator* NewFromGenerator(SkImageGenerator*, const SkIRect* subset = nullptr);
 
+    ~SkImageCacherator();
+
     const SkImageInfo& info() const { return fInfo; }
     uint32_t uniqueID() const { return fUniqueID; }
 
@@ -68,15 +69,19 @@ public:
                               int srcX, int srcY);
 
 private:
+    class SharedGenerator;
+    class ScopedGenerator;
+
     struct Validator {
         Validator(SkImageGenerator*, const SkIRect* subset);
+        ~Validator();
 
-        operator bool() const { return fGenerator.get(); }
+        operator bool() const { return fSharedGenerator.get(); }
 
-        std::unique_ptr<SkImageGenerator> fGenerator;
-        SkImageInfo                       fInfo;
-        SkIPoint                          fOrigin;
-        uint32_t                          fUniqueID;
+        sk_sp<SharedGenerator> fSharedGenerator;
+        SkImageInfo            fInfo;
+        SkIPoint               fOrigin;
+        uint32_t               fUniqueID;
     };
 
     SkImageCacherator(Validator*);
@@ -90,25 +95,10 @@ private:
                            SkImage::CachingHint, bool willBeMipped, SkSourceGammaTreatment);
 #endif
 
-    class ScopedGenerator {
-        SkImageCacherator* fCacher;
-    public:
-        ScopedGenerator(SkImageCacherator* cacher) : fCacher(cacher) {
-            fCacher->fMutexForGenerator.acquire();
-        }
-        ~ScopedGenerator() {
-            fCacher->fMutexForGenerator.release();
-        }
-        SkImageGenerator* operator->() const { return fCacher->fNotThreadSafeGenerator; }
-        operator SkImageGenerator*() const { return fCacher->fNotThreadSafeGenerator; }
-    };
-
-    SkMutex                         fMutexForGenerator;
-    SkAutoTDelete<SkImageGenerator> fNotThreadSafeGenerator;
-
-    const SkImageInfo   fInfo;
-    const SkIPoint      fOrigin;
-    const uint32_t      fUniqueID;
+    sk_sp<SharedGenerator> fSharedGenerator;
+    const SkImageInfo      fInfo;
+    const SkIPoint         fOrigin;
+    const uint32_t         fUniqueID;
 
     friend class GrImageTextureMaker;
     friend class SkImage;