Bug 848745 part 1. Add a scriptable API for converting CSS color names to RGB triples. r=dbaron,miker

dom/webidl/DummyBinding.webidl

@@ -13,6 +13,7 @@ interface DummyInterface {
   RTCConfiguration rtcConfiguration();
   CFStateChangeEventDict cfstateChangeEvent();
   USSDReceivedEventDict ussdReceivedEvent();
+  InspectorRGBTriple rgbTriple();
 };
 
 interface DummyInterfaceWorkers {

dom/webidl/InspectorUtils.webidl

@@ -0,0 +1,16 @@
+/* -*- Mode: IDL; 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/.
+ */
+dictionary InspectorRGBTriple {
+  /*
+   * NOTE: Using octet for RGB components is not generally OK, because
+   * they can be outside the 0-255 range, but for backwards-compatible
+   * named colors (which is what we use this dictionary for) the 0-255
+   * assumption is fine.
+   */
+  octet r = 0;
+  octet g = 0;
+  octet b = 0;
+};

dom/webidl/WebIDL.mk

@@ -119,6 +119,7 @@ webidl_files = \
   HTMLUListElement.webidl \
   IDBVersionChangeEvent.webidl \
   ImageData.webidl \
+  InspectorUtils.webidl \
   LinkStyle.webidl \
   LocalMediaStream.webidl \
   Location.webidl \

layout/inspector/public/inIDOMUtils.idl

@@ -16,7 +16,7 @@ interface nsIDOMFontFaceList;
 interface nsIDOMRange;
 interface nsIDOMCSSStyleSheet;
 
-[scriptable, uuid(ea7e58ad-da38-4d1e-b0fc-fd7fb5c560c9)]
+[scriptable, uuid(1d9c29dc-230a-441e-bba9-49104ffa185e)]
 interface inIDOMUtils : nsISupports
 {
   // CSS utilities
@@ -54,6 +54,10 @@ interface inIDOMUtils : nsISupports
 			   [optional] out unsigned long aCount,
 			   [retval, array, size_is(aCount)] out wstring aProps);
 
+  // Utilities for working with CSS colors
+  [implicit_jscontext]
+  jsval colorNameToRGB(in DOMString aColorName);
+
   // DOM Node utilities
   boolean isIgnorableWhitespace(in nsIDOMCharacterData aDataNode);
   // Returns the "parent" of a node.  The parent of a document node is the

layout/inspector/src/inDOMUtils.cpp

@@ -31,6 +31,7 @@
 #include "nsRuleWalker.h"
 #include "nsRuleProcessorData.h"
 #include "nsCSSRuleProcessor.h"
+#include "mozilla/dom/InspectorUtilsBinding.h"
 
 using namespace mozilla;
 using namespace mozilla::css;
@@ -414,6 +415,27 @@ inDOMUtils::GetCSSPropertyNames(uint32_t aFlags, uint32_t* aCount,
   return NS_OK;
 }
 
+NS_IMETHODIMP
+inDOMUtils::ColorNameToRGB(const nsAString& aColorName, JSContext* aCx,
+                           JS::Value* aValue)
+{
+  nscolor color;
+  if (!NS_ColorNameToRGB(aColorName, &color)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  InspectorRGBTriple triple;
+  triple.mR = NS_GET_R(color);
+  triple.mG = NS_GET_G(color);
+  triple.mB = NS_GET_B(color);
+
+  if (!triple.ToObject(aCx, nullptr, aValue)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 inDOMUtils::GetBindingURLs(nsIDOMElement *aElement, nsIArray **_retval)
 {