Enable debug builds in the Android framework

include/core/SkRefCnt.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.
  */
 
 #ifndef SkRefCnt_DEFINED
 #define SkRefCnt_DEFINED
 
@@ skipping 39 matching lines @@
             // prevents code conditioned on the result of unique() from running
             // until previous owners are all totally done calling unref().
             return true;
         }
         return false;
     }
 
     /** Increment the reference count. Must be balanced by a call to unref().
     */
     void ref() const {
+#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+        // Android employs some special subclasses that enable the fRefCnt to
+        // go to zero, but not below, prior to reusing the object.  This breaks
+        // the use of unique() on such objects and as such should be removed
+        // once the Android code is fixed.
+        SkASSERT(fRefCnt >= 0);
+#else
         SkASSERT(fRefCnt > 0);
+#endif
         (void)sk_atomic_fetch_add(&fRefCnt, +1, sk_memory_order_relaxed);  // No barrier required.
     }
 
     /** Decrement the reference count. If the reference count is 1 before the
         decrement, then delete the object. Note that if this is the case, then
         the object needs to have been allocated via new, and not on the stack.
     */
     void unref() const {
         SkASSERT(fRefCnt > 0);
         // A release here acts in place of all releases we "should" have been doing in ref().
@@ skipping 167 matching lines @@
             SkDELETE((const Derived*)this);
         }
     }
     void  deref() const { this->unref(); }
 
 private:
     mutable int32_t fRefCnt;
 };
 
 #endif