Bug 1501665 Part 1: Add a webidl property to Document to track if it's in an RDM pane. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D19235

--HG--
extra : source : be1026de486b096cee639ca584b1e8108c4b73cb

dom/base/Document.cpp

@@ -1340,7 +1340,8 @@ Document::Document(const char* aContentType)
       mSavedResolution(1.0f),
       mPendingInitialTranslation(false),
       mGeneration(0),
-      mCachedTabSizeGeneration(0) {
+      mCachedTabSizeGeneration(0),
+      mInRDMPane(false) {
   MOZ_LOG(gDocumentLeakPRLog, LogLevel::Debug, ("DOCUMENT %p created", this));
 
   SetIsInDocument();

dom/base/Document.h

@@ -3715,6 +3715,9 @@ class Document : public nsINode,
 
   void SetPrototypeDocument(nsXULPrototypeDocument* aPrototype);
 
+  bool InRDMPane() const { return mInRDMPane; }
+  void SetInRDMPane(bool aInRDMPane) { mInRDMPane = aInRDMPane; }
+
  protected:
   void DoUpdateSVGUseElementShadowTrees();
 
@@ -4678,6 +4681,8 @@ class Document : public nsINode,
   int32_t mCachedTabSizeGeneration;
   nsTabSizes mCachedTabSizes;
 
+  bool mInRDMPane;
+
  public:
   // Needs to be public because the bindings code pokes at it.
   js::ExpandoAndGeneration mExpandoAndGeneration;

dom/webidl/Document.webidl

@@ -567,3 +567,13 @@ partial interface Document {
     [SameObject, Pref="dom.security.featurePolicy.webidl.enabled"]
     readonly attribute Policy policy;
 };
+
+/**
+ * Document extensions to support devtools.
+ */
+partial interface Document {
+  // Is the Document embedded in a Responsive Design Mode pane. This property
+  // is not propegated to descendant Documents upon settting.
+  [ChromeOnly]
+  attribute boolean inRDMPane;
+};