Revert r10603 (Remove operator== from SkPaint) due to Chrome failures



git-svn-id: http://skia.googlecode.com/svn/trunk@10632 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/core/SkPaint.h b/include/core/SkPaint.h
index ac46760..fa0c61e 100644
--- a/include/core/SkPaint.h
+++ b/include/core/SkPaint.h
@@ -67,6 +67,11 @@
 
     SkPaint& operator=(const SkPaint&);
 
+    SK_API friend bool operator==(const SkPaint& a, const SkPaint& b);
+    friend bool operator!=(const SkPaint& a, const SkPaint& b) {
+        return !(a == b);
+    }
+
     void flatten(SkFlattenableWriteBuffer&) const;
     void unflatten(SkFlattenableReadBuffer&);