Discard atlas after every MultiPictureDraw::draw

tests/GpuLayerCacheTest.cpp

 /*
 * Copyright 2014 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 127 matching lines @@
         }
 
         for (int i = 0; i < kInitialNumLayers; ++i) {
             GrCachedLayer* layer = cache.findLayer(picture->uniqueID(), i+1, 
                                                    SkIRect::MakeEmpty(), SkMatrix::I());
             REPORTER_ASSERT(reporter, layer);
 
             // All the layers should be unlocked
             REPORTER_ASSERT(reporter, !layer->locked());
 
+            // When hoisted layers aren't cached they are aggressively removed
+            // from the atlas
+#if GR_CACHE_HOISTED_LAYERS
             // The first 4 layers should still be in the atlas.
             if (i < 4) {
                 REPORTER_ASSERT(reporter, layer->texture());
                 REPORTER_ASSERT(reporter, layer->isAtlased());
             } else {
+#endif
                 // The final layer should not be atlased.
                 REPORTER_ASSERT(reporter, NULL == layer->texture());
                 REPORTER_ASSERT(reporter, !layer->isAtlased());
+#if GR_CACHE_HOISTED_LAYERS
             }
+#endif
         }
 
         {
             // Add an additional layer. Since all the layers are unlocked this 
             // will force out the first atlased layer
             create_layers(reporter, &cache, *picture, 1, kInitialNumLayers);
             GrCachedLayer* layer = cache.findLayer(picture->uniqueID(), 
                                                    kInitialNumLayers+1, 
                                                    SkIRect::MakeEmpty(), SkMatrix::I());
             REPORTER_ASSERT(reporter, layer);
 
             lock_layer(reporter, &cache, layer);
             cache.removeUse(layer);
         }
 
         for (int i = 0; i < kInitialNumLayers+1; ++i) {
             GrCachedLayer* layer = cache.findLayer(picture->uniqueID(), i + 1,
                                                    SkIRect::MakeEmpty(), SkMatrix::I());
+#if GR_CACHE_HOISTED_LAYERS
             // 3 old layers plus the new one should be in the atlas.
             if (1 == i || 2 == i || 3 == i || 5 == i) {
                 REPORTER_ASSERT(reporter, layer);
                 REPORTER_ASSERT(reporter, !layer->locked());
                 REPORTER_ASSERT(reporter, layer->texture());
                 REPORTER_ASSERT(reporter, layer->isAtlased());
             } else if (4 == i) {
+#endif
                 // The one that was never atlased should still be around
                 REPORTER_ASSERT(reporter, layer);
 
                 REPORTER_ASSERT(reporter, NULL == layer->texture());
                 REPORTER_ASSERT(reporter, !layer->isAtlased());
+#if GR_CACHE_HOISTED_LAYERS
             } else {
                 // The one bumped out of the atlas (i.e., 0) should be gone
                 REPORTER_ASSERT(reporter, NULL == layer);
             }
+#endif
         }
 
         //--------------------------------------------------------------------
         // Free them all SkGpuDevice-style. This will not free up the
         // atlas' texture but will eliminate all the layers.
         TestingAccess::Purge(&cache, picture->uniqueID());
 
         REPORTER_ASSERT(reporter, TestingAccess::NumLayers(&cache) == 0);
         // TODO: add VRAM/resource cache check here
 
@@ skipping 16 matching lines @@
 
         picture.reset(NULL);
         cache.processDeletedPictures();
 
         REPORTER_ASSERT(reporter, TestingAccess::NumLayers(&cache) == 0);
         // TODO: add VRAM/resource cache check here
     }
 }
 
 #endif