Revert of Make GrResourceCache dynamically change between LRU and random replacement strategies.

src/gpu/GrDrawingManager.h

Index: src/gpu/GrDrawingManager.h
diff --git a/src/gpu/GrDrawingManager.h b/src/gpu/GrDrawingManager.h
index 3e90d3bd1784a87d34bb96022f53ddf8a6c7a682..9fced38163cc034d152037db63b6d25e7cf67f13 100644
--- a/src/gpu/GrDrawingManager.h
+++ b/src/gpu/GrDrawingManager.h
@@ -76,7 +76,6 @@
         , fSoftwarePathRenderer(nullptr)
         , fFlushState(context->getGpu(), context->resourceProvider())
         , fFlushing(false)
-        , fLastFlushType(GrResourceCache::FlushType::kExternal)
         , fIsImmediateMode(isImmediateMode) {
     }
 
@@ -108,7 +107,6 @@
 
     GrBatchFlushState                 fFlushState;
     bool                              fFlushing;
-    GrResourceCache::FlushType        fLastFlushType;
 
     bool                              fIsImmediateMode;
 };