Bug 1376964 - Part 1: Record the docshell's "bypass cache" flag on FontFaceSet. r=jfkthame

MozReview-Commit-ID: FW19nms4ZEB

--HG--
extra : rebase_source : c6407c336cd3187ed66781f717bff079616c97ba

layout/style/FontFaceSet.cpp

@@ -106,6 +106,7 @@ FontFaceSet::FontFaceSet(nsPIDOMWindowInner* aWindow, nsIDocument* aDocument)
   , mHasLoadingFontFaces(false)
   , mHasLoadingFontFacesIsDirty(false)
   , mDelayedLoadCheck(false)
+  , mBypassCache(false)
 {
   MOZ_ASSERT(mDocument, "We should get a valid document from the caller!");
 
@@ -118,6 +119,24 @@ FontFaceSet::FontFaceSet(nsPIDOMWindowInner* aWindow, nsIDocument* aDocument)
     mResolveLazilyCreatedReadyPromise = true;
   }
 
+  // Record the state of the "bypass cache" flags from the docshell now,
+  // since we want to look at them from style worker threads, and we can
+  // only get to the docshell through a weak pointer (which is only
+  // possible on the main thread).
+  //
+  // In theory the load type of a docshell could change after the document
+  // is loaded, but handling that doesn't seem too important.
+  if (nsCOMPtr<nsIDocShell> docShell = mDocument->GetDocShell()) {
+    uint32_t loadType;
+    uint32_t flags;
+    if ((NS_SUCCEEDED(docShell->GetLoadType(&loadType)) &&
+         ((loadType >> 16) & nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE)) ||
+        (NS_SUCCEEDED(docShell->GetDefaultLoadFlags(&flags)) &&
+         (flags & nsIRequest::LOAD_BYPASS_CACHE))) {
+      mBypassCache = true;
+    }
+  }
+
   if (!mDocument->DidFireDOMContentLoaded()) {
     mDocument->AddSystemEventListener(NS_LITERAL_STRING("DOMContentLoaded"),
                                       this, false, false);
@@ -1327,23 +1346,7 @@ FontFaceSet::CheckFontLoad(const gfxFontFaceSrc* aFontFaceSrc,
     *aPrincipal = aFontFaceSrc->mOriginPrincipal;
   }
 
-  *aBypassCache = false;
-
-  nsCOMPtr<nsIDocShell> docShell = mDocument->GetDocShell();
-  if (docShell) {
-    uint32_t loadType;
-    if (NS_SUCCEEDED(docShell->GetLoadType(&loadType))) {
-      if ((loadType >> 16) & nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE) {
-        *aBypassCache = true;
-      }
-    }
-    uint32_t flags;
-    if (NS_SUCCEEDED(docShell->GetDefaultLoadFlags(&flags))) {
-      if (flags & nsIRequest::LOAD_BYPASS_CACHE) {
-        *aBypassCache = true;
-      }
-    }
-  }
+  *aBypassCache = mBypassCache;
 
   return NS_OK;
 }

layout/style/FontFaceSet.h

@@ -355,6 +355,10 @@ private:
   // Whether CheckLoadingFinished calls should be ignored.  See comment in
   // OnFontFaceStatusChanged.
   bool mDelayedLoadCheck;
+
+  // Whether the docshell for our document indicated that loads should
+  // bypass the cache.
+  bool mBypassCache;
 };
 
 } // namespace dom