Allow painting multiple paint rects....

chrome/renderer/paint_aggregator_unittest.cc

Index: chrome/renderer/paint_aggregator_unittest.cc
===================================================================
--- chrome/renderer/paint_aggregator_unittest.cc	(revision 68349)
+++ chrome/renderer/paint_aggregator_unittest.cc	(working copy)
@@ -26,8 +26,8 @@
 TEST(PaintAggregator, DoubleDisjointInvalidation) {
   PaintAggregator greg;
 
-  gfx::Rect r1(2, 4, 2, 4);
-  gfx::Rect r2(4, 2, 4, 2);
+  gfx::Rect r1(2, 4, 2, 40);
+  gfx::Rect r2(4, 2, 40, 2);
 
   greg.InvalidateRect(r1);
   greg.InvalidateRect(r2);
@@ -36,11 +36,29 @@
 
   EXPECT_TRUE(greg.HasPendingUpdate());
   EXPECT_TRUE(greg.GetPendingUpdate().scroll_rect.IsEmpty());
-  ASSERT_EQ(2U, greg.GetPendingUpdate().paint_rects.size());
+  EXPECT_EQ(2U, greg.GetPendingUpdate().paint_rects.size());
 
   EXPECT_EQ(expected_bounds, greg.GetPendingUpdate().GetPaintBounds());
 }
 
+TEST(PaintAggregator, DisjointInvalidationsCombined) {
+  PaintAggregator greg;
+
+  gfx::Rect r1(2, 4, 2, 2);
+  gfx::Rect r2(4, 2, 2, 2);
+
+  greg.InvalidateRect(r1);
+  greg.InvalidateRect(r2);
+
+  gfx::Rect expected_bounds = r1.Union(r2);
+
+  EXPECT_TRUE(greg.HasPendingUpdate());
+  EXPECT_TRUE(greg.GetPendingUpdate().scroll_rect.IsEmpty());
+  ASSERT_EQ(1U, greg.GetPendingUpdate().paint_rects.size());
+
+  EXPECT_EQ(expected_bounds, greg.GetPendingUpdate().paint_rects[0]);
+}
+
 TEST(PaintAggregator, SingleScroll) {
   PaintAggregator greg;