Fix a leak in RefBase

this bug was introduced recently. it caused RefBase's weakref_impl
structure to be leaked for every RefBase object (about 20 bytes).

Change-Id: Id85e749ba04521199555dd701198edd097c313d4
diff --git a/libs/utils/RefBase.cpp b/libs/utils/RefBase.cpp
index 7de2633..ae55a61 100644
--- a/libs/utils/RefBase.cpp
+++ b/libs/utils/RefBase.cpp
@@ -418,18 +418,20 @@
     if (c != 1) return;
     
     if ((impl->mFlags&OBJECT_LIFETIME_WEAK) != OBJECT_LIFETIME_WEAK) {
-        if (impl->mStrong == INITIAL_STRONG_VALUE)
-            if (impl->mBase)
+        if (impl->mStrong == INITIAL_STRONG_VALUE) {
+            if (impl->mBase) {
                 impl->mBase->destroy();
-        else {
+            }
+        } else {
             // LOGV("Freeing refs %p of old RefBase %p\n", this, impl->mBase);
             delete impl;
         }
     } else {
         impl->mBase->onLastWeakRef(id);
         if ((impl->mFlags&OBJECT_LIFETIME_FOREVER) != OBJECT_LIFETIME_FOREVER) {
-            if (impl->mBase)
+            if (impl->mBase) {
                 impl->mBase->destroy();
+            }
         }
     }
 }
@@ -551,8 +553,10 @@
 
 RefBase::~RefBase()
 {
-    if (mRefs->mWeak == 0) {
-        delete mRefs;
+    if ((mRefs->mFlags & OBJECT_LIFETIME_WEAK) == OBJECT_LIFETIME_WEAK) {
+        if (mRefs->mWeak == 0) {
+            delete mRefs;
+        }
     }
 }