Adding missing SK_API identifier to class so that it's accessible in debug blink.

Review URL: https://codereview.chromium.org/14190016

git-svn-id: http://skia.googlecode.com/svn/trunk@8857 2bbb7eff-a529-9590-31e7-b0007b416f81

include/effects/SkPerlinNoiseShader.h

@@ -22,7 +22,7 @@
     The algorithm used is described here :
     http://www.w3.org/TR/SVG/filters.html#feTurbulenceElement
 */
-class SkPerlinNoiseShader : public SkShader {
+class SK_API SkPerlinNoiseShader : public SkShader {
     struct PaintingData;
 public:
     struct StitchData;