Clear document scope dirtiness in import StyleEngine.

third_party/WebKit/Source/web/tests/HTMLImportSheetsTest.cpp

Index: third_party/WebKit/Source/web/tests/HTMLImportSheetsTest.cpp
diff --git a/third_party/WebKit/Source/web/tests/HTMLImportSheetsTest.cpp b/third_party/WebKit/Source/web/tests/HTMLImportSheetsTest.cpp
index 386c25f15166edde940020af016bb7b5c2353fa8..b870d15cd0ef30ca98956f486914c6e57ca6c2b6 100644
--- a/third_party/WebKit/Source/web/tests/HTMLImportSheetsTest.cpp
+++ b/third_party/WebKit/Source/web/tests/HTMLImportSheetsTest.cpp
@@ -24,6 +24,15 @@ TEST_F(HTMLImportSheetsTest, NeedsActiveStyleUpdate) {
   import_resource.Complete("<style>div{}</style>");
 
   EXPECT_TRUE(GetDocument().GetStyleEngine().NeedsActiveStyleUpdate());
+  Document* import_doc =
+      toHTMLLinkElement(GetDocument().getElementById("link"))->import();
+  ASSERT_TRUE(import_doc);
+  EXPECT_TRUE(import_doc->GetStyleEngine().NeedsActiveStyleUpdate());
+
+  GetDocument().GetStyleEngine().UpdateActiveStyle();
+
+  EXPECT_FALSE(GetDocument().GetStyleEngine().NeedsActiveStyleUpdate());
+  EXPECT_FALSE(import_doc->GetStyleEngine().NeedsActiveStyleUpdate());
 }
 
 }  // namespace blink