cc: Define Region::Contains() to be A contains B if all points in B are also in A.

This means that Contains(empty) is always true.

Tests:
RegionTest.Contains

R=enne


Review URL: https://chromiumcodereview.appspot.com/11368149

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166812 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 9 insertions, 2 deletions

diff --git a/cc/occlusion_tracker.cc b/cc/occlusion_tracker.cc
index 50a453e..9c536d2 100644
--- a/cc/occlusion_tracker.cc
+++ b/cc/occlusion_tracker.cc
@@ -314,7 +314,7 @@ static inline bool testContentRectOccluded(const gfx::Rect& contentRect, const W
     gfx::RectF transformedRect = MathUtil::mapClippedRect(contentSpaceTransform, gfx::RectF(contentRect));
     // Take the gfx::ToEnclosingRect, as we want to include partial pixels in the test.
     gfx::Rect targetRect = gfx::IntersectRects(gfx::ToEnclosingRect(transformedRect), clipRectInTarget);
-    return targetRect.IsEmpty() || occlusion.Contains(targetRect);
+    return occlusion.Contains(targetRect);
 }
 
 template<typename LayerType, typename RenderSurfaceType>
diff --git a/cc/region.cc b/cc/region.cc
index 7a5e83c..f0fddc5 100644
--- a/cc/region.cc
+++ b/cc/region.cc
@@ -47,10 +47,14 @@ bool Region::Contains(gfx::Point point) const {
 }
 
 bool Region::Contains(gfx::Rect rect) const {
+  if (rect.IsEmpty())
+    return true;
   return skregion_.contains(ToSkIRect(rect));
 }
 
 bool Region::Contains(const Region& region) const {
+  if (region.IsEmpty())
+    return true;
   return skregion_.contains(region.skregion_);
 }
 
diff --git a/cc/region_unittest.cc b/cc/region_unittest.cc
index 2fd52d6..db0fc3c 100644
--- a/cc/region_unittest.cc
+++ b/cc/region_unittest.cc
@@ -224,7 +224,10 @@ TEST(RegionTest, ReadPastFullSpanVectorInIntersectsTest) {
   }
 
 TEST(RegionTest, ContainsRegion) {
-  TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect());
+  TEST_CONTAINS(gfx::Rect(), gfx::Rect());
+  TEST_CONTAINS(gfx::Rect(0, 0, 1, 1), gfx::Rect());
+  TEST_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect());
+
   TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect(0, 0, 1, 1));
   TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect(1, 1, 1, 1));