Make GrResourceCache use a priority queue of purgeable resources.

include/gpu/GrGpuResource.h

Index: include/gpu/GrGpuResource.h
diff --git a/include/gpu/GrGpuResource.h b/include/gpu/GrGpuResource.h
index baffd9ec8343bf04f9c716558003ddbf06b302ec..8a8b0b28c36546c1dfcf7b510bfb754de4dec70b 100644
--- a/include/gpu/GrGpuResource.h
+++ b/include/gpu/GrGpuResource.h
@@ -269,7 +269,7 @@ private:
 
     virtual size_t onGpuMemorySize() const = 0;
 
-    // See comments in CacheAccess.
+    // See comments in CacheAccess and ResourcePriv.
     bool setContentKey(const GrContentKey& contentKey);
     void removeContentKey();
     void notifyIsPurgeable() const;
@@ -283,9 +283,13 @@ private:
 
     static uint32_t CreateUniqueID();
 
-    // We're in an internal doubly linked list owned by GrResourceCache
+    // We're in an internal doubly linked list owned by GrResourceCache. TODO: Replace this with an
+    // array of unpurgeable resources in the cache.
     SK_DECLARE_INTERNAL_LLIST_INTERFACE(GrGpuResource);
 

[robertphillips, 2015/02/17 17:55:46]

Maybe more detail in the comment?
fCacheArrayIndex is the index of this resource in the purgeable priority queue.
It is zero when not in the queue.
fTimestamp ...

?

[bsalomon, 2015/02/17 19:18:43]

Done.

+    // These are used for cache bookkeeping
+    int                         fCacheArrayIndex;
+    uint32_t                    fTimestamp;
 
     static const size_t kInvalidGpuMemorySize = ~static_cast<size_t>(0);
     GrScratchKey                fScratchKey;