cc: Call PrepareTiles when becoming visible in browser only.

cc/trees/layer_tree_host_unittest.cc

 // Copyright 2011 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/trees/layer_tree_host.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/location.h"
@@ skipping 254 matching lines @@
   }
 
  private:
   FakeContentLayerClient client_;
 };
 
 // Note: With this test setup, we only get tiles flagged as REQUIRED_FOR_DRAW in
 // single threaded mode.
 SINGLE_THREAD_TEST_F(LayerTreeHostTestReadyToDrawNonEmpty);
 
+// This tests that we get the ready to draw signal eventually even if we become
+// invisible and then become visible again.
+class LayerTreeHostTestReadyToDrawVisibility
+    : public LayerTreeHostTestReadyToDrawNonEmpty {
+ public:
+  LayerTreeHostTestReadyToDrawVisibility()
+      : LayerTreeHostTestReadyToDrawNonEmpty(), did_commit_(false) {}
+
+  void CommitCompleteOnThread(LayerTreeHostImpl* host_impl) override {
+    EXPECT_FALSE(did_commit_);
+    did_commit_ = true;
+    PostSetVisibleToMainThread(false);
+  }
+
+  void DidSetVisibleOnImplTree(LayerTreeHostImpl* host_impl,
+                               bool visible) override {
+    if (!visible) {
+      EXPECT_TRUE(did_commit_);
+      EXPECT_FALSE(did_notify_ready_to_draw_);
+      PostSetVisibleToMainThread(true);
+    }
+  }
+
+ protected:
+  bool did_commit_;
+};
+
+SINGLE_THREAD_TEST_F(LayerTreeHostTestReadyToDrawVisibility);
+
 class LayerTreeHostFreeWorkerContextResourcesTest : public LayerTreeHostTest {
  public:
   scoped_ptr<FakeOutputSurface> CreateFakeOutputSurface() override {
     auto output_surface = make_scoped_ptr(new testing::StrictMock<
         MockSetWorkerContextShouldAggressivelyFreeResourcesOutputSurface>(
         delegating_renderer()));
 
     // At init, we expect one call to set visibility to true.
     testing::Expectation visibility_true =
         EXPECT_CALL(*output_surface,
@@ skipping 5767 matching lines @@
   void AfterTest() override {}
 
   std::vector<int> affected_by_page_scale_;
   std::vector<int> not_affected_by_page_scale_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeTestPageScaleFlags);
 
 }  // namespace
 }  // namespace cc