Attached ClipMaskManager to GPU resource freeing system

http://codereview.appspot.com/6208058/



git-svn-id: http://skia.googlecode.com/svn/trunk@3927 2bbb7eff-a529-9590-31e7-b0007b416f81

src/gpu/GrContext.cpp

@@ -110,6 +110,9 @@ void GrContext::resetContext() {
 
 void GrContext::freeGpuResources() {
     this->flush();
+    
+    fGpu->purgeResources();
+
     fTextureCache->removeAll();
     fFontCache->freeAll();
     // a path renderer may be holding onto resources

src/gpu/GrDrawTarget.h

@@ -545,6 +545,12 @@ public:
      */
     virtual void clear(const GrIRect* rect, GrColor color) = 0;
 
+    /**
+     * Release any resources that are cached but not currently in use. This
+     * is intended to give an application some recourse when resources are low.
+     */
+    virtual void purgeResources() {};
+
     ////////////////////////////////////////////////////////////////////////////
 
     /**

src/gpu/GrGpu.h

@@ -318,6 +318,12 @@ public:
     // GrDrawTarget overrides
     virtual void clear(const GrIRect* rect, GrColor color);
 
+    virtual void purgeResources() SK_OVERRIDE {
+        // The clip mask manager can rebuild all its clip masks so just
+        // get rid of them all.
+        fClipMaskManager.releaseResources();
+    }
+
     // After the client interacts directly with the 3D context state the GrGpu
     // must resync its internal state and assumptions about 3D context state.
     // Each time this occurs the GrGpu bumps a timestamp.