formalize generate->bitmap

include/core/SkImageGenerator.h

Index: include/core/SkImageGenerator.h
diff --git a/include/core/SkImageGenerator.h b/include/core/SkImageGenerator.h
index c84463def281302b995c9bd295f799cef8acc71a..5b96671c9894bdb96ee8ee4348711cac7261ec26 100644
--- a/include/core/SkImageGenerator.h
+++ b/include/core/SkImageGenerator.h
@@ -165,6 +165,23 @@ public:
     static SkImageGenerator* NewFromPicture(const SkISize&, const SkPicture*, const SkMatrix*,
                                             const SkPaint*);
 
+    bool tryGenerateBitmap(SkBitmap* bm) {
+        return this->tryGenerateBitmap(bm, nullptr);
+    }
+    bool tryGenerateBitmap(SkBitmap* bm, const SkImageInfo& info) {
+        return this->tryGenerateBitmap(bm, &info);
+    }
+    void generateBitmap(SkBitmap* bm) {
+        if (!this->tryGenerateBitmap(bm, nullptr)) {
+            sk_throw();
+        }
+    }
+    void generateBitmap(SkBitmap* bm, const SkImageInfo& info) {
+        if (!this->tryGenerateBitmap(bm, &info)) {
+            sk_throw();
+        }
+    }
+
 protected:
     SkImageGenerator(const SkImageInfo& info);
 
@@ -180,6 +197,8 @@ protected:
         return nullptr;
     }
 
+    bool tryGenerateBitmap(SkBitmap* bm, const SkImageInfo* optionalInfo);
+
 private:
     const SkImageInfo fInfo;
     const uint32_t fUniqueID;