Remove GrFontDescKey.

src/gpu/text/GrBatchFontCache.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrBatchFontCache_DEFINED
 #define GrBatchFontCache_DEFINED
 
 #include "GrBatchAtlas.h"
 #include "GrFontScaler.h"
 #include "GrGlyph.h"
 #include "SkGlyph.h"
 #include "SkTDynamicHash.h"
 #include "SkVarAlloc.h"
 
 class GrBatchFontCache;
 class GrGpu;
 
 /**
  *  The GrBatchTextStrike manages a pool of CPU backing memory for GrGlyphs.  This backing memory
- *  is indexed by a PackedID and GrFontScaler.  The GrFontScaler is what actually creates the mask.
+ *  is indexed by a PackedID and GrFontScaler. The GrFontScaler is what actually creates the mask.
+ *  The GrBatchTextStrike may outlive the generating GrFontScaler. However, it retains a copy
+ *  of it's SkDescriptor as a key to access (or regenerate) the GrFontScaler. GrBatchTextStrikes are
+ *  created by and owned by a GrBatchFontCache.
  */
 class GrBatchTextStrike : public SkNVRefCnt<GrBatchTextStrike> {
 public:
-    GrBatchTextStrike(GrBatchFontCache*, const GrFontDescKey* fontScalerKey);
+    /** Owner is the cache that owns this strike. */
+    GrBatchTextStrike(GrBatchFontCache* owner, const SkDescriptor& fontScalerKey);
     ~GrBatchTextStrike();
 
-    const GrFontDescKey* getFontScalerKey() const { return fFontScalerKey; }
-    GrBatchFontCache* getBatchFontCache() const { return fBatchFontCache; }
-
     inline GrGlyph* getGlyph(const SkGlyph& skGlyph, GrGlyph::PackedID packed,
                              GrFontScaler* scaler) {
         GrGlyph* glyph = fCache.find(packed);
         if (nullptr == glyph) {
             glyph = this->generateGlyph(skGlyph, packed, scaler);
         }
         return glyph;
     }
 
     // This variant of the above function is called by TextBatch.  At this point, it is possible
@@ skipping 25 matching lines @@
 
     // testing
     int countGlyphs() const { return fCache.count(); }
 
     // remove any references to this plot
     void removeID(GrBatchAtlas::AtlasID);
 
     // If a TextStrike is abandoned by the cache, then the caller must get a new strike
     bool isAbandoned() const { return fIsAbandoned; }
 
-    static const GrFontDescKey& GetKey(const GrBatchTextStrike& ts) {
-        return *(ts.fFontScalerKey);
+    static const SkDescriptor& GetKey(const GrBatchTextStrike& ts) {
+        return *ts.fFontScalerKey.getDesc();
     }
-    static uint32_t Hash(const GrFontDescKey& key) {
-        return key.getHash();
-    }
+
+    static uint32_t Hash(const SkDescriptor& desc) { return desc.getChecksum(); }
 
 private:
     SkTDynamicHash<GrGlyph, GrGlyph::PackedID> fCache;
-    SkAutoTUnref<const GrFontDescKey> fFontScalerKey;
+    SkAutoDescriptor fFontScalerKey;
     SkVarAlloc fPool;
 
     GrBatchFontCache* fBatchFontCache;
     int fAtlasedGlyphs;
     bool fIsAbandoned;
 
     GrGlyph* generateGlyph(const SkGlyph&, GrGlyph::PackedID, GrFontScaler*);
 
     friend class GrBatchFontCache;
 };
 
 /*
  * GrBatchFontCache manages strikes which are indexed by a GrFontScaler.  These strikes can then be
  * used to individual Glyph Masks.  The GrBatchFontCache also manages GrBatchAtlases, though this is
  * more or less transparent to the client(aside from atlasGeneration, described below).
  * Note - we used to initialize the backing atlas for the GrBatchFontCache at initialization time.
  * However, this caused a regression, even when the GrBatchFontCache was unused.  We now initialize
  * the backing atlases lazily.  Its not immediately clear why this improves the situation.
  */
 class GrBatchFontCache {
 public:
     GrBatchFontCache(GrContext*);
     ~GrBatchFontCache();
     // The user of the cache may hold a long-lived ref to the returned strike. However, actions by
     // another client of the cache may cause the strike to be purged while it is still reffed.
     // Therefore, the caller must check GrBatchTextStrike::isAbandoned() if there are other
     // interactions with the cache since the strike was received.
     inline GrBatchTextStrike* getStrike(GrFontScaler* scaler) {
-        GrBatchTextStrike* strike = fCache.find(*(scaler->getKey()));
+        GrBatchTextStrike* strike = fCache.find(scaler->getKey());
         if (nullptr == strike) {
             strike = this->generateStrike(scaler);
         }
         return strike;
     }
 
     void freeAll();
 
     // if getTexture returns nullptr, the client must not try to use other functions on the
     // GrBatchFontCache which use the atlas.  This function *must* be called first, before other
@@ skipping 87 matching lines @@
     }
 
     GrBatchAtlas* getAtlas(GrMaskFormat format) const {
         int atlasIndex = MaskFormatToAtlasIndex(format);
         SkASSERT(fAtlases[atlasIndex]);
         return fAtlases[atlasIndex];
     }
 
     static void HandleEviction(GrBatchAtlas::AtlasID, void*);
 
+    using StrikeHash = SkTDynamicHash<GrBatchTextStrike, SkDescriptor>;
     GrContext* fContext;
-    SkTDynamicHash<GrBatchTextStrike, GrFontDescKey> fCache;
+    StrikeHash fCache;
     GrBatchAtlas* fAtlases[kMaskFormatCount];
     GrBatchTextStrike* fPreserveStrike;
     GrBatchAtlasConfig fAtlasConfigs[kMaskFormatCount];
 };
 
 #endif