If Ashmem cache fails pinCache, do not reallocate.

src/lazy/SkLruImageCache.cpp

Index: src/lazy/SkLruImageCache.cpp
diff --git a/src/lazy/SkLruImageCache.cpp b/src/lazy/SkLruImageCache.cpp
index 62e29535966e8674acbe3cae3999dfeb8adca68a..342a3e5496d0f222f43930206f8f0cda48c05a86 100644
--- a/src/lazy/SkLruImageCache.cpp
+++ b/src/lazy/SkLruImageCache.cpp
@@ -131,7 +131,6 @@ void SkLruImageCache::releaseCache(intptr_t ID) {
 }
 
 void SkLruImageCache::throwAwayCache(intptr_t ID) {
-    SkASSERT(ID != SkImageCache::UNINITIALIZED_ID);
     SkAutoMutexAcquire ac(&fMutex);
     CachedPixels* pixels = this->findByID(ID);
     if (pixels != NULL) {
@@ -154,6 +153,9 @@ void SkLruImageCache::removePixels(CachedPixels* pixels) {
 
 CachedPixels* SkLruImageCache::findByID(intptr_t ID) const {
     // Mutex is already locked.
+    if (SkImageCache::UNINITIALIZED_ID == ID) {
+        return NULL;
+    }
     Iter iter;
     // Start from the head, most recently used.
     CachedPixels* pixels = iter.init(fLRU, Iter::kHead_IterStart);