Implement SkImageFilter support in the compositor.

cc/layer.h

Index: cc/layer.h
diff --git a/cc/layer.h b/cc/layer.h
index cfb80b04fcedbb4108249e2dbcc26bc3ecf167fa..6e55d243894ec3c4be47d677e3220cc7523c4bc3 100644
--- a/cc/layer.h
+++ b/cc/layer.h
@@ -22,6 +22,8 @@ class WebAnimationDelegate;
 class WebLayerScrollClient;
 }
 
+class SkImageFilter;
+
 namespace cc {
 
 class CCActiveAnimation;
@@ -95,6 +97,9 @@ public:
     void setFilters(const WebKit::WebFilterOperations&);
     const WebKit::WebFilterOperations& filters() const { return m_filters; }
 
+    void setFilter(SkImageFilter* filter);

[danakj, 2012/10/19 19:34:24]

same, setImageFilter?

[Stephen White, 2012/10/19 21:34:50]

Same as above.

+    SkImageFilter* filter() const { return m_filter; }
+
     // Background filters are filters applied to what is behind this layer, when they are viewed through non-opaque
     // regions in this layer. They are used through the WebLayer interface, and are not exposed to HTML.
     void setBackgroundFilters(const WebKit::WebFilterOperations&);
@@ -335,6 +340,7 @@ private:
     float m_debugBorderWidth;
     std::string m_debugName;
     float m_opacity;
+    SkImageFilter* m_filter;

[jamesr, 2012/10/19 19:15:30]

Should this be a SkTAutoUnref<> or something of that nature?  What should happen
if a filter is set on a Layer and then the layer is destroyed before we
pushPropertiesTo - we should drop a ref, right?

[Stephen White, 2012/10/19 21:34:50]

You're totally right.  Wow, what a doozy.

I've added explicit unrefs in the destructor so I can still do forward decl's,
and because Skia's smart pointers are so dumb.  :|

     WebKit::WebFilterOperations m_filters;
     WebKit::WebFilterOperations m_backgroundFilters;
     float m_anchorPointZ;