Clear Image Decode Cache on Navigation

cc/tiles/software_image_decode_cache_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/tiles/software_image_decode_cache.h"
 
 #include "cc/paint/draw_image.h"
 #include "cc/resources/resource_format.h"
 #include "cc/test/test_tile_task_runner.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 1428 matching lines @@
   EXPECT_EQ(100, decoded_draw_image_49.image()->height());
 
   EXPECT_EQ(decoded_draw_image_50.image(), decoded_draw_image_49.image());
 
   cache.DrawWithImageFinished(draw_image_50, decoded_draw_image_50);
   cache.UnrefImage(draw_image_50);
   cache.DrawWithImageFinished(draw_image_49, decoded_draw_image_49);
   cache.UnrefImage(draw_image_49);
 }
 
+TEST(SoftwareImageDecodeCacheTest, ClearCache) {
+  TestSoftwareImageDecodeCache cache;
+  bool is_decomposable = true;
+  SkFilterQuality quality = kHigh_SkFilterQuality;
+
+  for (int i = 0; i < 10; ++i) {
+    sk_sp<SkImage> image = CreateImage(100, 100);
+    DrawImage draw_image(
+        image, SkIRect::MakeWH(image->width(), image->height()), quality,
+        CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable));
+    scoped_refptr<TileTask> task;
+    bool need_unref = cache.GetTaskForImageAndRef(
+        draw_image, ImageDecodeCache::TracingInfo(), &task);
+    EXPECT_TRUE(need_unref);
+    EXPECT_TRUE(task);
+    TestTileTaskRunner::ProcessTask(task.get());
+    cache.UnrefImage(draw_image);
+  }
+
+  EXPECT_EQ(10u, cache.GetNumCacheEntriesForTesting());
+
+  // Tell our cache to clear resources.
+  cache.ClearCache();
+
+  EXPECT_EQ(0u, cache.GetNumCacheEntriesForTesting());
+}
+
 }  // namespace
 }  // namespace cc