Provide a method to remove inserted style sheet

third_party/WebKit/Source/core/dom/StyleEngineTest.cpp

Index: third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
diff --git a/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp b/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
index da6ca9d5d107a85ed355a43256baf4db658dd210..e5691d68ab4681869f48ab948d753154c3432ba0 100644
--- a/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
+++ b/third_party/WebKit/Source/core/dom/StyleEngineTest.cpp
@@ -87,20 +87,51 @@ TEST_F(StyleEngineTest, AnalyzedInject) {
   EXPECT_EQ(MakeRGB(255, 0, 0),
             t1->GetComputedStyle()->VisitedDependentColor(CSSPropertyColor));
 
-  unsigned before_count = GetStyleEngine().StyleForElementCount();
+  const unsigned initial_count = GetStyleEngine().StyleForElementCount();
 
-  StyleSheetContents* parsed_sheet =
+  StyleSheetContents* green_parsed_sheet =
       StyleSheetContents::Create(CSSParserContext::Create(GetDocument()));
-  parsed_sheet->ParseString("#t1 { color: green }");
-  GetStyleEngine().InjectAuthorSheet(parsed_sheet);
+  green_parsed_sheet->ParseString("#t1 { color: green }");
+  int green_css_id = GetStyleEngine().InjectAuthorSheet(green_parsed_sheet);
+  EXPECT_EQ(1, green_css_id);
+  EXPECT_EQ(1u, GetStyleEngine().InjectedAuthorStyleSheets().size());
   GetDocument().View()->UpdateAllLifecyclePhases();
 
-  unsigned after_count = GetStyleEngine().StyleForElementCount();
-  EXPECT_EQ(1u, after_count - before_count);
+  EXPECT_EQ(1u, GetStyleEngine().StyleForElementCount() - initial_count);
 
   ASSERT_TRUE(t1->GetComputedStyle());
   EXPECT_EQ(MakeRGB(0, 128, 0),
             t1->GetComputedStyle()->VisitedDependentColor(CSSPropertyColor));
+
+  StyleSheetContents* blue_parsed_sheet =
+      StyleSheetContents::Create(CSSParserContext::Create(GetDocument()));
+  blue_parsed_sheet->ParseString("#t1 { color: blue }");
+  int blue_css_id = GetStyleEngine().InjectAuthorSheet(blue_parsed_sheet);
+  EXPECT_EQ(2, blue_css_id);
+  EXPECT_EQ(2u, GetStyleEngine().InjectedAuthorStyleSheets().size());
+  GetDocument().View()->UpdateAllLifecyclePhases();
+
+  EXPECT_EQ(2u, GetStyleEngine().StyleForElementCount() - initial_count);
+
+  ASSERT_TRUE(t1->GetComputedStyle());
+  EXPECT_EQ(MakeRGB(0, 0, 255),
+            t1->GetComputedStyle()->VisitedDependentColor(CSSPropertyColor));
+
+  EXPECT_TRUE(GetStyleEngine().RemoveInjectedAuthorSheet(green_css_id));
+  EXPECT_EQ(1u, GetStyleEngine().InjectedAuthorStyleSheets().size());
+  GetDocument().View()->UpdateAllLifecyclePhases();
+  EXPECT_EQ(3u, GetStyleEngine().StyleForElementCount() - initial_count);
+  ASSERT_TRUE(t1->GetComputedStyle());
+  EXPECT_EQ(MakeRGB(0, 0, 255),
+            t1->GetComputedStyle()->VisitedDependentColor(CSSPropertyColor));
+
+  EXPECT_TRUE(GetStyleEngine().RemoveInjectedAuthorSheet(blue_css_id));
+  EXPECT_EQ(0u, GetStyleEngine().InjectedAuthorStyleSheets().size());
+  GetDocument().View()->UpdateAllLifecyclePhases();
+  EXPECT_EQ(4u, GetStyleEngine().StyleForElementCount() - initial_count);
+  ASSERT_TRUE(t1->GetComputedStyle());
+  EXPECT_EQ(MakeRGB(255, 0, 0),
+            t1->GetComputedStyle()->VisitedDependentColor(CSSPropertyColor));
 }
 
 TEST_F(StyleEngineTest, TextToSheetCache) {