Revert "Add a new GrResourceCache purging mechanism for purging unused resources."

This reverts commit fbb56ce83fc717b7c6722324bbccd1ae73c350a4.

Reason for revert: Chrome's ancient libstdc++ doesn't like use of steady_clock

Original change's description:
> Add a new GrResourceCache purging mechanism for purging unused resources.
> 
> The client may call GrContext::purgeResourceNotUsedSince() with a stead_clock::time_point and all resources that have been purgeable since before that time point are purged.
> 
> This is intended to replace the "max unused flushes" purging mechanism once Chrome adopts it.
> 
> Change-Id: I28881dd2959cc01c0acca81b2d6001ee5626439d
> Reviewed-on: https://skia-review.googlesource.com/8920
> Commit-Queue: Brian Salomon <bsalomon@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Reviewed-by: Eric Karl <ericrk@google.com>
> 

TBR=bsalomon@google.com,robertphillips@google.com,ericrk@google.com,reviews@skia.org,ericrk@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I3baa3b2e80302315b757d4d625732459e13795d4
Reviewed-on: https://skia-review.googlesource.com/10004
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/src/gpu/GrResourceCache.h b/src/gpu/GrResourceCache.h
index aef9a5c8df..5f08a51aa0 100644
--- a/src/gpu/GrResourceCache.h
+++ b/src/gpu/GrResourceCache.h
@@ -50,9 +50,8 @@ public:
     static const int    kDefaultMaxCount            = 2 * (1 << 12);
     // Default maximum number of bytes of gpu memory of budgeted resources in the cache.
     static const size_t kDefaultMaxSize             = 96 * (1 << 20);
-    // Default number of external flushes a budgeted resources can go unused in the cache before it
-    // is purged. Using a value <= 0 disables this feature. This will be removed once Chrome
-    // starts using time-based purging.
+    // Default number of external flushes a budgeted resources can go unused in the cache before it 
+    // is purged. Using a value <= 0 disables this feature.
     static const int    kDefaultMaxUnusedFlushes =
             1  * /* flushes per frame */
             60 * /* fps */
@@ -160,9 +159,6 @@ public:
     /** Purges all resources that don't have external owners. */
     void purgeAllUnlocked();
 
-    /** Purge all resources not used since the passed in time. */
-    void purgeResourcesNotUsedSince(std::chrono::steady_clock::time_point);
-
     /** Returns true if the cache would like a flush to occur in order to make more resources
         purgeable. */
     bool requestsFlush() const { return fRequestFlush; }