diff -r 000000000000 -r 6474c204b198 layout/style/nsIStyleSheet.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/nsIStyleSheet.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * interface representing a collection of style data attached to a
+ * document, which may be or be combined into a style rule processor
+ */
+
+#ifndef nsIStyleSheet_h___
+#define nsIStyleSheet_h___
+
+#include "mozilla/MemoryReporting.h"
+#include <stdio.h>
+#include "nsISupports.h"
+
+class nsString;
+class nsIURI;
+class nsIDocument;
+
+// IID for the nsIStyleSheet interface
+// 3eb34a60-04bd-41d9-9f60-882694e61c38
+#define NS_ISTYLE_SHEET_IID     \
+{ 0x3eb34a60, 0x04bd, 0x41d9,   \
+ { 0x9f, 0x60, 0x88, 0x26, 0x94, 0xe6, 0x1c, 0x38 } }
+
+/**
+ * A style sheet is a thing associated with a document that has style
+ * rules.  Those style rules can be reached in one of two ways, depending
+ * on which level of the nsStyleSet it is in:
+ *   1) It can be |QueryInterface|d to nsIStyleRuleProcessor
+ *   2) It can be |QueryInterface|d to nsCSSStyleSheet, with which the
+ *      |nsStyleSet| uses an |nsCSSRuleProcessor| to access the rules.
+ */
+class nsIStyleSheet : public nsISupports {
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_ISTYLE_SHEET_IID)
+
+  // basic style sheet data
+  virtual nsIURI* GetSheetURI() const = 0;
+  virtual nsIURI* GetBaseURI() const = 0;
+  virtual void GetTitle(nsString& aTitle) const = 0;
+  virtual void GetType(nsString& aType) const = 0;
+  virtual bool HasRules() const = 0;
+
+  /**
+   * Whether the sheet is applicable.  A sheet that is not applicable
+   * should never be inserted into a style set.  A sheet may not be
+   * applicable for a variety of reasons including being disabled and
+   * being incomplete.
+   *
+   */
+  virtual bool IsApplicable() const = 0;
+
+  /**
+   * Set the stylesheet to be enabled.  This may or may not make it
+   * applicable.  Note that this WILL inform the sheet's document of
+   * its new applicable state if the state changes but WILL NOT call
+   * BeginUpdate() or EndUpdate() on the document -- calling those is
+   * the caller's responsibility.  This allows use of SetEnabled when
+   * batched updates are desired.  If you want updates handled for
+   * you, see nsIDOMStyleSheet::SetDisabled().
+   */
+  virtual void SetEnabled(bool aEnabled) = 0;
+
+  /**
+   * Whether the sheet is complete.
+   */
+  virtual bool IsComplete() const = 0;
+  virtual void SetComplete() = 0;
+
+  // style sheet owner info
+  virtual nsIStyleSheet* GetParentSheet() const = 0;  // may be null
+  virtual nsIDocument* GetOwningDocument() const = 0; // may be null
+  virtual void SetOwningDocument(nsIDocument* aDocument) = 0;
+
+#ifdef DEBUG
+  virtual void List(FILE* out = stdout, int32_t aIndent = 0) const = 0;
+#endif
+
+  virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const = 0;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsIStyleSheet, NS_ISTYLE_SHEET_IID)
+
+#endif /* nsIStyleSheet_h___ */