Fix for 510931, merge to m44

src/gpu/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 "GrDrawTarget.h"
 #include "GrFontScaler.h"
 #include "GrGlyph.h"
+#include "SkGlyph.h"
 #include "SkTDynamicHash.h"
 #include "SkVarAlloc.h"
 
 class GrBatchFontCache;
 class GrBatchTarget;
 class GrGpu;
 
 /**
  *  The GrBatchTextStrike manages a pool of CPU backing memory for Glyph Masks.  This backing memory
  *  is abstracted by GrGlyph, and indexed by a PackedID and GrFontScaler.  The GrFontScaler is what
  *  actually creates the mask.
  */
 class GrBatchTextStrike : public SkNVRefCnt<GrBatchTextStrike> {
 public:
     GrBatchTextStrike(GrBatchFontCache*, const GrFontDescKey* fontScalerKey);
     ~GrBatchTextStrike();
 
     const GrFontDescKey* getFontScalerKey() const { return fFontScalerKey; }
     GrBatchFontCache* getBatchFontCache() const { return fBatchFontCache; }
 
-    inline GrGlyph* getGlyph(GrGlyph::PackedID packed, GrFontScaler* scaler) {
+    inline GrGlyph* getGlyph(const SkGlyph& skGlyph, GrGlyph::PackedID packed,
+                             GrFontScaler* scaler) {
         GrGlyph* glyph = fCache.find(packed);
         if (NULL == glyph) {
-            glyph = this->generateGlyph(packed, scaler);
+            glyph = this->generateGlyph(skGlyph, packed, scaler);
         }
         return glyph;
     }
 
-    // returns true if glyph successfully added to texture atlas, false otherwise
-    bool addGlyphToAtlas(GrBatchTarget*, GrGlyph*, GrFontScaler*);
+    // This variant of the above function is called by TextBatch.  At this point, it is possible
+    // that the maskformat of the glyph differs from what we expect.  In these cases we will just
+    // draw a clear square.
+    // skbug:4143 crbug:510931
+    inline GrGlyph* getGlyph(const SkGlyph& skGlyph, GrGlyph::PackedID packed,
+                             GrMaskFormat expectedMaskFormat, GrFontScaler* scaler) {
+        GrGlyph* glyph = fCache.find(packed);
+        if (NULL == glyph) {
+            glyph = this->generateGlyph(skGlyph, packed, scaler);
+            glyph->fMaskFormat = expectedMaskFormat;
+        }
+        return glyph;
+    }
+
+    // returns true if glyph successfully added to texture atlas, false otherwise.  If the glyph's
+    // mask format has changed, then addGlyphToAtlas will draw a clear box.  This will almost never
+    // happen.
+    // TODO we can handle some of these cases if we really want to, but the long term solution is to
+    // get the actual glyph image itself when we get the glyph metrics.
+    bool addGlyphToAtlas(GrBatchTarget*, GrGlyph*, GrFontScaler*, const SkGlyph&,
+                         GrMaskFormat expectedMaskFormat);
 
     // 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 uint32_t Hash(const GrFontDescKey& key) {
         return key.getHash();
     }
 
 private:
     SkTDynamicHash<GrGlyph, GrGlyph::PackedID> fCache;
     SkAutoTUnref<const GrFontDescKey> fFontScalerKey;
     SkVarAlloc fPool;
 
     GrBatchFontCache* fBatchFontCache;
     int fAtlasedGlyphs;
     bool fIsAbandoned;
 
-    GrGlyph* generateGlyph(GrGlyph::PackedID packed, GrFontScaler* scaler);
+    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
@@ skipping 100 matching lines @@
 
     static void HandleEviction(GrBatchAtlas::AtlasID, void*);
 
     GrContext* fContext;
     SkTDynamicHash<GrBatchTextStrike, GrFontDescKey> fCache;
     GrBatchAtlas* fAtlases[kMaskFormatCount];
     GrBatchTextStrike* fPreserveStrike;
 };
 
 #endif