move readPixels from bitmap -> pixmap

include/core/SkPixmap.h

Index: include/core/SkPixmap.h
diff --git a/include/core/SkPixmap.h b/include/core/SkPixmap.h
index a2ce6cd7889fc10b73f34feb61ea00378da7d312..3b554cf7ac120ef4b88d365f6a73e7c565968022 100644
--- a/include/core/SkPixmap.h
+++ b/include/core/SkPixmap.h
@@ -44,7 +44,8 @@ public:
     SkAlphaType alphaType() const { return fInfo.alphaType(); }
     bool isOpaque() const { return fInfo.isOpaque(); }
 
-    int64_t getSafeSize64() const { return fInfo.getSafeSize64(fRowBytes); }
+    uint64_t getSize64() const { return sk_64_mul(fInfo.height(), fRowBytes); }
+    uint64_t getSafeSize64() const { return fInfo.getSafeSize64(fRowBytes); }
     size_t getSafeSize() const { return fInfo.getSafeSize(fRowBytes); }
 
     const uint32_t* addr32() const {
@@ -94,6 +95,20 @@ public:
         return const_cast<uint8_t*>(this->addr8(x, y));
     }
 
+    // copy methods
+
+    bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes,
+                    int srcX, int srcY) const;
+    bool readPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRowBytes) const {
+        return this->readPixels(dstInfo, dstPixels, dstRowBytes, 0, 0);
+    }
+    bool readPixels(const SkPixmap& dst, int srcX, int srcY) const {
+        return this->readPixels(dst.info(), dst.writable_addr(), dst.rowBytes(), srcX, srcY);
+    }
+    bool readPixels(const SkPixmap& dst) const {
+        return this->readPixels(dst.info(), dst.writable_addr(), dst.rowBytes(), 0, 0);
+    }
+
 private:
     const void*     fPixels;
     SkColorTable*   fCTable;