Provide a method to remove inserted style sheet

third_party/WebKit/Source/core/dom/StyleEngine.h

Index: third_party/WebKit/Source/core/dom/StyleEngine.h
diff --git a/third_party/WebKit/Source/core/dom/StyleEngine.h b/third_party/WebKit/Source/core/dom/StyleEngine.h
index 6b7206772724c3bbbfce8c77bf4964bafec46250..53205fd8668e605275db78127c766b912f4acfe2 100644
--- a/third_party/WebKit/Source/core/dom/StyleEngine.h
+++ b/third_party/WebKit/Source/core/dom/StyleEngine.h
@@ -31,6 +31,7 @@
 #define StyleEngine_h
 
 #include <memory>
+#include <utility>
 #include "core/CoreExport.h"
 #include "core/css/ActiveStyleSheets.h"
 #include "core/css/CSSFontSelectorClient.h"
@@ -93,7 +94,7 @@ class CORE_EXPORT StyleEngine final
   const HeapVector<TraceWrapperMember<StyleSheet>>&
   StyleSheetsForStyleSheetList(TreeScope&);
 
-  const HeapVector<TraceWrapperMember<CSSStyleSheet>>&
+  const HeapVector<std::pair<int, TraceWrapperMember<CSSStyleSheet>>>&
   InjectedAuthorStyleSheets() const {
     return injected_author_style_sheets_;
   }
@@ -112,7 +113,8 @@ class CORE_EXPORT StyleEngine final
   void ViewportRulesChanged();
   void HtmlImportAddedOrRemoved();
 
-  void InjectAuthorSheet(StyleSheetContents* author_sheet);
+  int InjectAuthorSheet(StyleSheetContents* author_sheet);
+  bool RemoveInjectedAuthorSheet(int id);
   CSSStyleSheet& EnsureInspectorStyleSheet();
   RuleSet* WatchedSelectorsRuleSet() {
     return global_rule_set_.WatchedSelectorsRuleSet();
@@ -344,7 +346,8 @@ class CORE_EXPORT StyleEngine final
   int pending_render_blocking_stylesheets_ = 0;
   int pending_body_stylesheets_ = 0;
 
-  HeapVector<TraceWrapperMember<CSSStyleSheet>> injected_author_style_sheets_;
+  HeapVector<std::pair<int, TraceWrapperMember<CSSStyleSheet>>>
+      injected_author_style_sheets_;
   Member<CSSStyleSheet> inspector_style_sheet_;
 
   TraceWrapperMember<DocumentStyleSheetCollection>
@@ -387,6 +390,8 @@ class CORE_EXPORT StyleEngine final
   std::unique_ptr<StyleResolverStats> style_resolver_stats_;
   unsigned style_for_element_count_ = 0;
 
+  volatile int injected_author_sheets_id_count_ = 0;

[rune, 2017/05/16 09:00:58]

Why volatile?

I would have used a plain unsigned instead.

[limasdf, 2017/05/18 12:32:53]

Done.

+
   friend class StyleEngineTest;
 };