Correct a possible free after use.

src/core/SkGlyphCache.cpp

Index: src/core/SkGlyphCache.cpp
diff --git a/src/core/SkGlyphCache.cpp b/src/core/SkGlyphCache.cpp
index add0ea9f00e83f4a8be41140fa32d062724b6473..61122048690d66d85aee8d832ec86d7e04b06022 100644
--- a/src/core/SkGlyphCache.cpp
+++ b/src/core/SkGlyphCache.cpp
@@ -428,12 +428,10 @@ SkGlyphCache* SkGlyphCache::VisitCache(
         }
 
         cache = new SkGlyphCache(typeface, desc, ctx);
-
-        globals.attachCacheToHead(cache);
     }
 
-    AutoValidate av(cache);
     AutoAcquire ac(globals.fLock);

[mtklein, 2015/09/10 20:35:47]

Does this make sense?

// Do not lock globals.fLock here.
cache->fMapMutex.acquireShared();
if (!proc(cache, context)) {
   cache->fMapMutex.releaseShared();
   globals.attachCacheToHead(cache);
   return nullptr;
}
cache->fRefCount += 1;
globals.attachCacheToHead(cache);
return cache;

+    globals.internalAttachCacheToHead(cache);
 
     cache->fMapMutex.acquireShared();
     if (!proc(cache, context)) {   // need to reattach
@@ -534,9 +532,8 @@ void SkGlyphCache::VisitAll(Visitor visitor, void* context) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void SkGlyphCache_Globals::attachCacheToHead(SkGlyphCache* cache) {
-    AutoAcquire ac(fLock);
-
+void SkGlyphCache_Globals::internalAttachCacheToHead(SkGlyphCache* cache) {
+    this->internalPurge();
     fCacheCount += 1;
     cache->fRefCount += 1;
     // Access to cache->fMemoryUsed is single threaded until internalMoveToHead.
@@ -546,8 +543,6 @@ void SkGlyphCache_Globals::attachCacheToHead(SkGlyphCache* cache) {
 
     this->validate();
     cache->validate();
-
-    this->internalPurge();
 }
 
 SkGlyphCache* SkGlyphCache_Globals::internalGetTail() const {