--- a/gfx/ipc/GfxMessageUtils.h
+++ b/gfx/ipc/GfxMessageUtils.h
@@ -724,16 +724,30 @@ struct ParamTraits<mozilla::layers::Fram
     nsCString str;
     if (!ReadParam(aMsg, aIter, &str)) {
       return false;
     }
     aResult->SetContentDescription(str);
     return true;
   }
 
+  // We need this helper because we can't get the address of a bitfield to
+  // pass directly to ReadParam. So instead we read it into a temporary bool
+  // and set the bitfield using a setter function
+  static bool ReadBoolForBitfield(const Message* aMsg, void** aIter,
+        paramType* aResult, void (paramType::*aSetter)(bool))
+  {
+    bool value;
+    if (ReadParam(aMsg, aIter, &value)) {
+      (aResult->*aSetter)(value);
+      return true;
+    }
+    return false;
+  }
+
   static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
   {
     return (ReadParam(aMsg, aIter, &aResult->mScrollId) &&
             ReadParam(aMsg, aIter, &aResult->mScrollParentId) &&
             ReadParam(aMsg, aIter, &aResult->mPresShellResolution) &&
             ReadParam(aMsg, aIter, &aResult->mCompositionBounds) &&
             ReadParam(aMsg, aIter, &aResult->mDisplayPort) &&
             ReadParam(aMsg, aIter, &aResult->mCriticalDisplayPort) &&
@@ -750,25 +764,25 @@ struct ParamTraits<mozilla::layers::Fram
             ReadParam(aMsg, aIter, &aResult->mViewport) &&
             ReadParam(aMsg, aIter, &aResult->mExtraResolution) &&
             ReadParam(aMsg, aIter, &aResult->mBackgroundColor) &&
             ReadContentDescription(aMsg, aIter, aResult) &&
             ReadParam(aMsg, aIter, &aResult->mLineScrollAmount) &&
             ReadParam(aMsg, aIter, &aResult->mPageScrollAmount) &&
             ReadParam(aMsg, aIter, &aResult->mClipRect) &&
             ReadParam(aMsg, aIter, &aResult->mMaskLayerIndex) &&
-            ReadParam(aMsg, aIter, &aResult->mIsRootContent) &&
-            ReadParam(aMsg, aIter, &aResult->mHasScrollgrab) &&
-            ReadParam(aMsg, aIter, &aResult->mUpdateScrollOffset) &&
-            ReadParam(aMsg, aIter, &aResult->mDoSmoothScroll) &&
-            ReadParam(aMsg, aIter, &aResult->mUseDisplayPortMargins) &&
-            ReadParam(aMsg, aIter, &aResult->mAllowVerticalScrollWithWheel) &&
-            ReadParam(aMsg, aIter, &aResult->mIsLayersIdRoot) &&
-            ReadParam(aMsg, aIter, &aResult->mUsesContainerScrolling) &&
-            ReadParam(aMsg, aIter, &aResult->mIsScrollInfoLayer));
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetIsRootContent) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetHasScrollgrab) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetUpdateScrollOffset) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetDoSmoothScroll) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetUseDisplayPortMargins) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetAllowVerticalScrollWithWheel) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetIsLayersIdRoot) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetUsesContainerScrolling) &&
+            ReadBoolForBitfield(aMsg, aIter, aResult, &paramType::SetIsScrollInfoLayer));
   }
 };
 
 template<>
 struct ParamTraits<mozilla::layers::TextureFactoryIdentifier>
 {
   typedef mozilla::layers::TextureFactoryIdentifier paramType;
 

--- a/gfx/layers/FrameMetrics.h
+++ b/gfx/layers/FrameMetrics.h
@@ -718,56 +718,65 @@ private:
   Maybe<ParentLayerIntRect> mClipRect;
 
   // An extra clip mask layer to use when compositing a layer with this
   // FrameMetrics. This is an index into the MetricsMaskLayers array on
   // the Layer.
   Maybe<size_t> mMaskLayerIndex;
 
   // Whether or not this is the root scroll frame for the root content document.
-  bool mIsRootContent;
+  bool mIsRootContent:1;
 
   // Whether or not this frame is for an element marked 'scrollgrab'.
-  bool mHasScrollgrab;
+  bool mHasScrollgrab:1;
 
   // Whether mScrollOffset was updated by something other than the APZ code, and
   // if the APZC receiving this metrics should update its local copy.
-  bool mUpdateScrollOffset;
+  bool mUpdateScrollOffset:1;
 
   // When mDoSmoothScroll, the scroll offset should be animated to
   // smoothly transition to mScrollOffset rather than be updated instantly.
-  bool mDoSmoothScroll;
+  bool mDoSmoothScroll:1;
 
   // If this is true then we use the display port margins on this metrics,
   // otherwise use the display port rect.
-  bool mUseDisplayPortMargins;
+  bool mUseDisplayPortMargins:1;
 
   // Whether or not the frame can be vertically scrolled with a mouse wheel.
-  bool mAllowVerticalScrollWithWheel;
+  bool mAllowVerticalScrollWithWheel:1;
 
   // Whether these framemetrics are for the root scroll frame (root element if
   // we don't have a root scroll frame) for its layers id.
-  bool mIsLayersIdRoot;
+  bool mIsLayersIdRoot:1;
 
   // True if scrolling using containers, false otherwise. This can be removed
   // when containerful scrolling is eliminated.
-  bool mUsesContainerScrolling;
+  bool mUsesContainerScrolling:1;
 
   // Whether or not this frame has a "scroll info layer" to capture events.
-  bool mIsScrollInfoLayer;
+  bool mIsScrollInfoLayer:1;
 
   // WARNING!!!!
   //
   // When adding new fields to FrameMetrics, the following places should be
   // updated to include them (as needed):
   //    FrameMetrics::operator ==
   //    AsyncPanZoomController::NotifyLayersUpdated
   //    The ParamTraits specialization in GfxMessageUtils.h
   //
   // Please add new fields above this comment.
+
+
+  // Private helpers for IPC purposes
+  void SetUpdateScrollOffset(bool aValue) {
+    mUpdateScrollOffset = aValue;
+  }
+  void SetDoSmoothScroll(bool aValue) {
+    mDoSmoothScroll = aValue;
+  }
 };
 
 /**
  * This class allows us to uniquely identify a scrollable layer. The
  * mLayersId identifies the layer tree (corresponding to a child process
  * and/or tab) that the scrollable layer belongs to. The mPresShellId
  * is a temporal identifier (corresponding to the document loaded that
  * contains the scrollable layer, which may change over time). The