Added explicit cache clearing

http://codereview.appspot.com/6492094/



git-svn-id: http://skia.googlecode.com/svn/trunk@5444 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrResourceCache.h b/src/gpu/GrResourceCache.h
index 59320b0..e6b412e 100644
--- a/src/gpu/GrResourceCache.h
+++ b/src/gpu/GrResourceCache.h
@@ -288,6 +288,11 @@
      */
     void purgeAllUnlocked();
 
+    /**
+     * Allow cache to purge unused resources to obey resource limitations
+     */
+    void purgeAsNeeded();
+
 #if GR_DEBUG
     void validate() const;
 #else
@@ -301,7 +306,6 @@
 private:
     void internalDetach(GrResourceEntry*, bool);
     void attachToHead(GrResourceEntry*, bool);
-    void purgeAsNeeded();
 
     void removeInvalidResource(GrResourceEntry* entry);