Document return value of SkPaint::operator==.

include/core/SkPaint.h

 
 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
@@ skipping 38 matching lines @@
 */
 
 class SK_API SkPaint {
 public:
     SkPaint();
     SkPaint(const SkPaint& paint);
     ~SkPaint();
 
     SkPaint& operator=(const SkPaint&);
 
+    /** operator== may give false negatives: two paints that draw equivalently
+        may return false.  It will never give false positives: two paints that
+        are not equivalent always return false.
+    */
     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(SkWriteBuffer&) const;
     void unflatten(SkReadBuffer&);
 
     /** Restores the paint to its initial settings.
     */
@@ skipping 1061 matching lines @@
     friend class SkCanonicalizePaint;
 
 #ifdef SK_BUILD_FOR_ANDROID
     // In order for the == operator to work properly this must be the last field
     // in the struct so that we can do a memcmp to this field's offset.
     uint32_t        fGenerationID;
 #endif
 };
 
 #endif