set key data in duplicate scratch key unit test

tests/ResourceCacheTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #if SK_SUPPORT_GPU
 
 #include "GrContext.h"
@@ skipping 113 matching lines @@
     if (NULL == context) {
         return;
     }
     context->setResourceCacheLimits(5, 30000);
     GrResourceCache* cache = context->getResourceCache();
     SkDEBUGCODE(GrResourceCache2* cache2 = context->getResourceCache2();)
     cache->purgeAllUnlocked();
     SkASSERT(0 == cache->getCachedResourceCount() && 0 == cache->getCachedResourceBytes());
 
     GrCacheID::Key keyData;
+    memset(&keyData, 0, sizeof(keyData));
     GrCacheID::Domain domain = GrResourceKey::ScratchDomain();
     GrResourceKey::ResourceType t = GrResourceKey::GenerateResourceType();
     GrResourceKey scratchKey(GrCacheID(domain, keyData), t, 0);
 
     // Create two resources that have the same scratch key.
     TestResource* a = new TestResource(context->getGpu(), scratchKey);
     TestResource* b = new TestResource(context->getGpu(), scratchKey);
     a->setSize(11);
     b->setSize(12);
     // Scratch resources are registered with GrResourceCache2 just by existing. There are 2.
@@ skipping 312 matching lines @@
 
     // The below tests create their own mock contexts.
     test_duplicate_content_key(reporter);
     test_duplicate_scratch_key(reporter);
     test_purge_invalidated(reporter);
     test_cache_delete_on_destruction(reporter);
     test_resource_size_changed(reporter);
 }
 
 #endif