Bug 1297963 - Part 2: Add URLValueData comparison functions that work OMT. r=emilio

MozReview-Commit-ID: IfTsuOJ0iXI

layout/style/nsCSSValue.cpp

@@ -2678,6 +2678,23 @@ css::URLValueData::URIEquals(const URLValueData& aOther) const
          mLocalURLFlag == aOther.mLocalURLFlag;
 }
 
+bool
+css::URLValueData::DefinitelyEqualURIs(const URLValueData& aOther) const
+{
+  return mBaseURI == aOther.mBaseURI &&
+         (mString == aOther.mString ||
+          NS_strcmp(nsCSSValue::GetBufferValue(mString),
+                    nsCSSValue::GetBufferValue(aOther.mString)));
+}
+
+bool
+css::URLValueData::DefinitelyEqualURIsAndPrincipal(
+    const URLValueData& aOther) const
+{
+  return mOriginPrincipal == aOther.mOriginPrincipal &&
+         DefinitelyEqualURIs(aOther);
+}
+
 nsIURI*
 css::URLValueData::GetURI() const
 {

layout/style/nsCSSValue.h

@@ -122,6 +122,19 @@ struct URLValueData
   // false in that case).
   bool MaybeUnresolvedURIEquals(const URLValueData& aOther) const;
 
+  // Returns true iff we know for sure, by comparing the mBaseURI pointer,
+  // the specified url() value mString, and the mLocalURLFlag, that these
+  // two URLValueData objects represent the same computed url() value.
+  //
+  // Doesn't look at mReferrer or mOriginPrincipal.
+  //
+  // Safe to call from any thread.
+  bool DefinitelyEqualURIs(const URLValueData& aOther) const;
+
+  // Smae as DefinitelyEqualURIs but additionally compares the nsIPrincipal
+  // pointers of the two URLValueData objects.
+  bool DefinitelyEqualURIsAndPrincipal(const URLValueData& aOther) const;
+
   nsIURI* GetURI() const;
 
   size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;