Bug 570620, part b: Fix a hidden header depedency and add a PresShell::GetLayerManager() helper. r=tn

layout/base/nsIPresShell.h

@@ -109,6 +109,10 @@ namespace mozilla {
 namespace dom {
 class Element;
 } // namespace dom
+
+namespace layers{
+class LayerManager;
+} // namespace layers
 } // namespace mozilla
 
 // Flags to pass to SetCapturingContent
@@ -133,8 +137,8 @@ typedef struct CapturingContentInfo {
 } CapturingContentInfo;
 
 #define NS_IPRESSHELL_IID     \
-  { 0x318f7b6c, 0x56be, 0x4256, \
-    { 0xa3, 0x09, 0xff, 0xdc, 0xde, 0x04, 0x63, 0xf6 } }
+  { 0xb2d3df3b, 0x54ba, 0x44cf, \
+    { 0x8c, 0xfd, 0x24, 0x84, 0x3e, 0xac, 0x27, 0x96 } }
 
 // Constants for ScrollContentIntoView() function
 #define NS_PRESSHELL_SCROLL_TOP      0
@@ -187,6 +191,9 @@ NS_DEFINE_STATIC_IID_ACCESSOR(nsIPresShell_base, NS_IPRESSHELL_IID)
 
 class nsIPresShell : public nsIPresShell_base
 {
+protected:
+  typedef mozilla::layers::LayerManager LayerManager;
+
 public:
   virtual NS_HIDDEN_(nsresult) Init(nsIDocument* aDocument,
                                    nsPresContext* aPresContext,
@@ -1024,6 +1031,12 @@ public:
    */
   virtual already_AddRefed<nsPIDOMWindow> GetRootWindow() = 0;
 
+  /**
+   * Get the layer manager for the widget of the root view, if it has
+   * one.
+   */
+  virtual LayerManager* GetLayerManager() = 0;
+
   /**
    * Refresh observer management.
    */

layout/base/nsLayoutUtils.cpp

@@ -747,6 +747,24 @@ nsLayoutUtils::GetNearestScrollableFrame(nsIFrame* aFrame)
   return nsnull;
 }
 
+//static
+PRBool
+nsLayoutUtils::HasPseudoStyle(nsIContent* aContent,
+                              nsStyleContext* aStyleContext,
+                              nsCSSPseudoElements::Type aPseudoElement,
+                              nsPresContext* aPresContext)
+{
+  NS_PRECONDITION(aPresContext, "Must have a prescontext");
+
+  nsRefPtr<nsStyleContext> pseudoContext;
+  if (aContent) {
+    pseudoContext = aPresContext->StyleSet()->
+      ProbePseudoElementStyle(aContent->AsElement(), aPseudoElement,
+                              aStyleContext);
+  }
+  return pseudoContext != nsnull;
+}
+
 nsPoint
 nsLayoutUtils::GetDOMEventCoordinatesRelativeTo(nsIDOMEvent* aDOMEvent, nsIFrame* aFrame)
 {

layout/base/nsLayoutUtils.h

@@ -357,18 +357,7 @@ public:
   static PRBool HasPseudoStyle(nsIContent* aContent,
                                nsStyleContext* aStyleContext,
                                nsCSSPseudoElements::Type aPseudoElement,
-                               nsPresContext* aPresContext)
-  {
-    NS_PRECONDITION(aPresContext, "Must have a prescontext");
-
-    nsRefPtr<nsStyleContext> pseudoContext;
-    if (aContent) {
-      pseudoContext = aPresContext->StyleSet()->
-        ProbePseudoElementStyle(aContent->AsElement(), aPseudoElement,
-                                aStyleContext);
-    }
-    return pseudoContext != nsnull;
-  }
+                               nsPresContext* aPresContext);
 
   /**
    * If this frame is a placeholder for a float, then return the float,

layout/base/nsPresShell.cpp

@@ -207,6 +207,8 @@
 
 #include "mozilla/FunctionTimer.h"
 
+#include "Layers.h"
+
 #ifdef NS_FUNCTION_TIMER
 #define NS_TIME_FUNCTION_DECLARE_DOCURL                \
   nsCAutoString docURL__("N/A");                       \
@@ -228,8 +230,8 @@ static NS_DEFINE_IID(kRangeCID,     NS_RANGE_CID);
 #include "nsIMemoryReporter.h"
 
 using namespace mozilla;
-using namespace mozilla::layers;
 using namespace mozilla::dom;
+using namespace mozilla::layers;
 
 PRBool nsIPresShell::gIsAccessibilityActive = PR_FALSE;
 CapturingContentInfo nsIPresShell::gCaptureInfo;
@@ -810,6 +812,8 @@ public:
 
   virtual already_AddRefed<nsPIDOMWindow> GetRootWindow();
 
+  virtual LayerManager* GetLayerManager();
+
   //nsIViewObserver interface
 
   NS_IMETHOD Paint(nsIView* aDisplayRoot,
@@ -5836,6 +5840,19 @@ struct PaintParams {
   nscolor mBackgroundColor;
 };
 
+LayerManager* PresShell::GetLayerManager()
+{
+  NS_ASSERTION(mViewManager, "Should have view manager");
+
+  nsIView* rootView;
+  if (NS_SUCCEEDED(mViewManager->GetRootView(rootView)) && rootView) {
+    if (nsIWidget* widget = rootView->GetWidget()) {
+      return widget->GetLayerManager();
+    }
+  }
+  return nsnull;
+}
+
 static void DrawThebesLayer(ThebesLayer* aLayer,
                             gfxContext* aContext,
                             const nsIntRegion& aRegionToDraw,