Only allow forced fragmentainer breaks at class A break points.

third_party/WebKit/Source/core/layout/PaginationTest.cpp

Index: third_party/WebKit/Source/core/layout/PaginationTest.cpp
diff --git a/third_party/WebKit/Source/core/layout/PaginationTest.cpp b/third_party/WebKit/Source/core/layout/PaginationTest.cpp
index 7df64f8dc652e04f96c77aeb5387dfea033125d3..ecc4dd66402df75f1834d4d29675c9c05aa0ad23 100644
--- a/third_party/WebKit/Source/core/layout/PaginationTest.cpp
+++ b/third_party/WebKit/Source/core/layout/PaginationTest.cpp
@@ -145,8 +145,10 @@ TEST_F(PaginationStrutTest, InnerBlockWithBreakBefore)
         "</div>");
     EXPECT_EQ(0, strutForBox("block1"));
     EXPECT_EQ(0, strutForLine("block1", 0));
-    EXPECT_EQ(0, strutForBox("block2"));
-    EXPECT_EQ(48, strutForBox("innerBlock"));
+    // There's no class A break point before #innerBlock (they only exist *between* siblings), so
+    // the break is propagated and applied before #block2.
+    EXPECT_EQ(50, strutForBox("block2"));
+    EXPECT_EQ(0, strutForBox("innerBlock"));
     EXPECT_EQ(0, strutForLine("innerBlock", 0));
 }