Ensure that pinch-zoom scrollbar animations trigger a draw

cc/trees/layer_tree_host_unittest_animation.cc

 // Copyright 2012 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 "cc/animation/animation_curve.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/animation/timing_function.h"
 #include "cc/layers/layer.h"
@@ skipping 747 matching lines @@
   int added_animations_;
   int started_times_;
   int finished_times_;
   FakeContentLayerClient client_;
   scoped_refptr<FakeContentLayer> content_;
 };
 
 MULTI_THREAD_TEST_F(
     LayerTreeHostAnimationTestCheckerboardDoesntStartAnimations);
 
+// Test that creating a pinch-zoom scrollbar animation leads to AnimateLayers
+// being called.
+class LayerTreeHostAnimationTestPinchZoomScrollbars
+    : public LayerTreeHostAnimationTest {
+ public:
+  LayerTreeHostAnimationTestPinchZoomScrollbars()
+      : root_layer_(ContentLayer::Create(&client_)),
+        started_times_(0) {}
+
+  virtual void InitializeSettings(LayerTreeSettings* settings) OVERRIDE {
+    settings->use_pinch_zoom_scrollbars = true;
+  }
+
+  virtual void BeginTest() OVERRIDE {
+    root_layer_->SetIsDrawable(true);
+    root_layer_->SetBounds(gfx::Size(100, 100));
+    layer_tree_host()->SetRootLayer(root_layer_);

[danakj, 2013/04/17 20:54:09]

Can you set up the layer tree in SetupTree() instead of BeginTest()? Then you'll
get a viewport of the right size and stuff. Just make sure you call
LayerTreeHostAnimationTest::SetupTree(); after you set the root layer so it can
set up the rest.

The page scale stuff can stay here.

[ajuma, 2013/04/18 18:42:51]

Done.

+    layer_tree_host()->SetPageScaleFactorAndLimits(0.5, 0.5, 0.9);

[danakj, 2013/04/17 20:54:09]

These are floats. 0.5f etc

[wjmaclean, 2013/04/17 20:56:54]

Minor nit: we generally would only have pinch zoom scrollbars if page scale > 1.
Typical values might be

SetPageScaleFactorAndLimits(1.xx, 1, 4); // Probably '2' is less preferable to
1.xx in terms of generality.

[danakj, 2013/04/17 21:01:03]

Oh, is this test actually triggering the scrollbars then, or is it testing
something else? Can you verify that it fails without your change?

[ajuma, 2013/04/18 18:42:51]

Done.

+    PostSetNeedsCommitToMainThread();
+  }
+
+  virtual void AnimateLayers(LayerTreeHostImpl* host_impl,
+                             base::TimeTicks monotonic_time) OVERRIDE {
+    if (host_impl->active_tree()->page_scale_factor() == 1.0)

[danakj, 2013/04/17 20:54:09]

1.f

[ajuma, 2013/04/18 18:42:51]

Done.

+      return;
+
+    if (started_times_ == 0) {

[danakj, 2013/04/17 20:54:09]

seems like a good spot for a switch?

[ajuma, 2013/04/18 18:42:51]

Done.

+      host_impl->active_tree()->DidBeginScroll();
+      started_times_++;
+      return;
+    }
+
+    if (started_times_ == 1) {
+      host_impl->active_tree()->DidEndScroll();
+      started_times_++;
+      return;
+    }
+
+    if (started_times_ == 2)
+      EndTest();
+  }
+
+  virtual void AfterTest() OVERRIDE {}
+
+ private:
+  FakeContentLayerClient client_;
+  scoped_refptr<ContentLayer> root_layer_;
+  int started_times_;
+};
+
+SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostAnimationTestPinchZoomScrollbars);
+
 }  // namespace
 }  // namespace cc