SkImage method for detecting lazy decoding

BUG=skia:4224
R=reed@google.com

Review URL: https://codereview.chromium.org/1305453007
diff --git a/src/image/SkImage_Base.h b/src/image/SkImage_Base.h
index 38f9906..46cd3de 100644
--- a/src/image/SkImage_Base.h
+++ b/src/image/SkImage_Base.h
@@ -60,7 +60,7 @@
 
     virtual SkShader* onNewShader(SkShader::TileMode,
                                   SkShader::TileMode,
-                                  const SkMatrix* localMatrix) const { return NULL; };
+                                  const SkMatrix* localMatrix) const { return NULL; }
 
     // newWidth > 0, newHeight > 0, subset either NULL or a proper subset of this bounds
     virtual SkImage* onNewImage(int newWidth, int newHeight, const SkIRect* subset,
@@ -69,6 +69,8 @@
 
     virtual bool onAsLegacyBitmap(SkBitmap*, LegacyBitmapMode) const;
 
+    virtual bool onIsLazyGenerated() const { return false; }
+
 private:
     const SkSurfaceProps fProps;