Mac Overlays: Add unittests for CALayerTree

BUG=

Review URL: https://codereview.chromium.org/1711503002

Cr-Commit-Position: refs/heads/master@{#376042}

content/common/gpu/ca_layer_tree_mac.h

@@ -13,6 +13,7 @@
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
+#include "content/common/content_export.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/transform.h"
@@ -22,7 +23,7 @@ namespace content {
 // The CALayerTree will construct a hierarchy of CALayers from a linear list,
 // using the algorithm and structure referenced described in
 // https://docs.google.com/document/d/1DtSN9zzvCF44_FQPM7ie01UxGHagQ66zfF5L9HnigQY/edit?usp=sharing
-class CALayerTree {
+class CONTENT_EXPORT CALayerTree {
  public:
   CALayerTree();
 

content/common/gpu/ca_layer_tree_mac.mm

@@ -303,7 +303,7 @@ void CALayerTree::ClipAndSortingLayer::CommitToCA(
     DCHECK(old_layer->ca_layer);
     std::swap(ca_layer, old_layer->ca_layer);
     update_is_clipped = old_layer->is_clipped != is_clipped;
-    update_clip_rect = old_layer->clip_rect != clip_rect;
+    update_clip_rect = update_is_clipped || old_layer->clip_rect != clip_rect;
   } else {
     ca_layer.reset([[CALayer alloc] init]);
     [ca_layer setAnchorPoint:CGPointZero];

content/content_tests.gypi

@@ -663,6 +663,7 @@
       'common/dwrite_font_platform_win_unittest.cc',
       'common/fileapi/file_system_util_unittest.cc',
       'common/gpu/client/gpu_memory_buffer_impl_shared_memory_unittest.cc',
+      'common/gpu/ca_layer_tree_unittest_mac.mm',
       'common/gpu/gpu_channel_manager_unittest.cc',
       'common/gpu/gpu_channel_test_common.cc',
       'common/gpu/gpu_channel_test_common.h',