Bug 1418930 Part 1: Define and use a method nsContentUtils::CORSModeToLoadImageFlags to standardize conversion of CORS modes to load image flags. r=bz

MozReview-Commit-ID: AqsEUhFYxH6

--HG--
extra : rebase_source : 94ab4f3b1e5729cce8a2572c949b174fc74fd878

dom/base/nsContentUtils.cpp

@@ -3701,6 +3701,20 @@ nsContentUtils::IsImageInCache(nsIURI* aURI, nsIDocument* aDocument)
     return (NS_SUCCEEDED(rv) && props);
 }
 
+// static
+int32_t
+nsContentUtils::CORSModeToLoadImageFlags(mozilla::CORSMode aMode)
+{
+  switch (aMode) {
+  case CORS_ANONYMOUS:
+    return imgILoader::LOAD_CORS_ANONYMOUS;
+  case CORS_USE_CREDENTIALS:
+    return imgILoader::LOAD_CORS_USE_CREDENTIALS;
+  default:
+    return 0;
+  }
+}
+
 // static
 nsresult
 nsContentUtils::LoadImage(nsIURI* aURI, nsINode* aContext,

dom/base/nsContentUtils.h

@@ -22,6 +22,7 @@
 #include "js/RootingAPI.h"
 #include "mozilla/dom/FromParser.h"
 #include "mozilla/BasicEvents.h"
+#include "mozilla/CORSMode.h"
 #include "mozilla/EventForwards.h"
 #include "mozilla/GuardObjects.h"
 #include "mozilla/TaskCategory.h"
@@ -825,6 +826,14 @@ public:
    */
   static bool DocumentInactiveForImageLoads(nsIDocument* aDocument);
 
+  /**
+   * Convert a CORSMode into the corresponding imgILoader flags for
+   * passing to LoadImage.
+   * @param aMode CORS mode to convert
+   * @return a bitfield suitable to bitwise OR with other nsIRequest flags
+   */
+  static int32_t CORSModeToLoadImageFlags(mozilla::CORSMode aMode);
+
   /**
    * Method to start an image load.  This does not do any security checks.
    * This method will attempt to make aURI immutable; a caller that wants to

dom/base/nsDocument.cpp

@@ -9254,20 +9254,9 @@ nsDocument::MaybePreLoadImage(nsIURI* uri, const nsAString &aCrossOriginAttr,
     return;
   }
 
-  nsLoadFlags loadFlags = nsIRequest::LOAD_NORMAL;
-  switch (Element::StringToCORSMode(aCrossOriginAttr)) {
-  case CORS_NONE:
-    // Nothing to do
-    break;
-  case CORS_ANONYMOUS:
-    loadFlags |= imgILoader::LOAD_CORS_ANONYMOUS;
-    break;
-  case CORS_USE_CREDENTIALS:
-    loadFlags |= imgILoader::LOAD_CORS_USE_CREDENTIALS;
-    break;
-  default:
-    MOZ_CRASH("Unknown CORS mode!");
-  }
+  nsLoadFlags loadFlags = nsIRequest::LOAD_NORMAL |
+                          nsContentUtils::CORSModeToLoadImageFlags(
+                            Element::StringToCORSMode(aCrossOriginAttr));
 
   nsContentPolicyType policyType =
     aIsImgSet ? nsIContentPolicy::TYPE_IMAGESET :

dom/base/nsImageLoadingContent.cpp

@@ -963,13 +963,9 @@ nsImageLoadingContent::LoadImage(nsIURI* aNewURI,
              "Principal mismatch?");
 #endif
 
-  nsLoadFlags loadFlags = aLoadFlags;
-  int32_t corsmode = GetCORSMode();
-  if (corsmode == CORS_ANONYMOUS) {
-    loadFlags |= imgILoader::LOAD_CORS_ANONYMOUS;
-  } else if (corsmode == CORS_USE_CREDENTIALS) {
-    loadFlags |= imgILoader::LOAD_CORS_USE_CREDENTIALS;
-  }
+  nsLoadFlags loadFlags = aLoadFlags |
+                          nsContentUtils::CORSModeToLoadImageFlags(
+                            GetCORSMode());
 
   // get document wide referrer policy
   // if referrer attributes are enabled in preferences, load img referrer attribute