SkPDF: cache metrics once.

src/pdf/SkPDFCanon.h

Index: src/pdf/SkPDFCanon.h
diff --git a/src/pdf/SkPDFCanon.h b/src/pdf/SkPDFCanon.h
index a0241e308f469d43e679f8440e7d6bb33d273fd8..2da9e52f70fb3ef15649fbe4129a3c6e8207e070 100644
--- a/src/pdf/SkPDFCanon.h
+++ b/src/pdf/SkPDFCanon.h
@@ -14,6 +14,7 @@
 #include "SkTHash.h"
 #include "SkBitmapKey.h"
 
+class SkAdvancedTypefaceMetrics;
 class SkPDFFont;
 
 /**
@@ -35,19 +36,11 @@ class SkPDFFont;
  */
 class SkPDFCanon : SkNoncopyable {
 public:
-    ~SkPDFCanon() { this->reset(); }
+    ~SkPDFCanon();
 
     // reset to original setting, unrefs all objects.
     void reset();
 
-    // Returns exact match if there is one.  If not, it returns nullptr.
-    // If there is no exact match, but there is a related font, we
-    // still return nullptr, but also set *relatedFont.
-    SkPDFFont* findFont(uint32_t fontID,
-                        uint16_t glyphID,
-                        SkPDFFont** relatedFont) const;
-    void addFont(SkPDFFont* font, uint32_t fontID, uint16_t fGlyphID);
-
     sk_sp<SkPDFObject> findFunctionShader(const SkPDFShader::State&) const;
     void addFunctionShader(sk_sp<SkPDFObject>, SkPDFShader::State);
 
@@ -63,7 +56,9 @@ public:
     sk_sp<SkPDFObject> findPDFBitmap(SkBitmapKey key) const;
     void addPDFBitmap(SkBitmapKey key, sk_sp<SkPDFObject>);
 
-    SkTHashMap<uint32_t, bool> fCanEmbedTypeface;
+    SkTHashMap<uint32_t, SkAdvancedTypefaceMetrics*> fTypefaceMetrics;
+    SkTHashMap<uint32_t, SkPDFDict*> fFontDescriptors;
+    SkTHashMap<uint64_t, SkPDFFont*> fFontMap;
 
     SkPixelSerializer* getPixelSerializer() const { return fPixelSerializer.get(); }
     void setPixelSerializer(sk_sp<SkPixelSerializer> ps) {
@@ -75,13 +70,6 @@ public:
     sk_sp<SkPDFArray> makeRangeObject();
 
 private:
-    struct FontRec {
-        SkPDFFont* fFont;
-        uint32_t fFontID;
-        uint16_t fGlyphID;
-    };
-    SkTDArray<FontRec> fFontRecords;
-
     struct ShaderRec {
         SkPDFShader::State fShaderState;
         sk_sp<SkPDFObject> fShaderObject;