Revert "Add pre-Flush callback to GrDrawingManager"

This reverts commit d222ec492f5d0229986f529134d083e589bcc4a9.

Reason for revert: TegraX1 Vulkan bot

Original change's description:
> Add pre-Flush callback to GrDrawingManager
> 
> This will allow internal systems (e.g., fonts & path renderers) to create pre-flush atlases.
> 
> Depends on: https://skia-review.googlesource.com/c/8988/ (Allow GrSurfaceProxy-derived classes to use flags when instantiating)
> 
> Change-Id: I307796595d651cf376838bff1f9e4385c3753547
> Reviewed-on: https://skia-review.googlesource.com/8679
> Commit-Queue: Robert Phillips <robertphillips@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> 

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

Change-Id: I852648adc12d2aa58cd09c57d961c340d657776c
Reviewed-on: https://skia-review.googlesource.com/9735
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrTextureOpList.cpp b/src/gpu/GrTextureOpList.cpp
index d396b2a..d70daa2 100644
--- a/src/gpu/GrTextureOpList.cpp
+++ b/src/gpu/GrTextureOpList.cpp
@@ -45,7 +45,11 @@
 #endif
 
 void GrTextureOpList::prepareOps(GrOpFlushState* flushState) {
-    // MDB TODO: add SkASSERT(this->isClosed());
+    // Semi-usually the GrOpLists are already closed at this point, but sometimes Ganesh
+    // needs to flush mid-draw. In that case, the SkGpuDevice's GrOpLists won't be closed
+    // but need to be flushed anyway. Closing such GrOpLists here will mean new
+    // GrOpLists will be created to replace them if the SkGpuDevice(s) write to them again.
+    this->makeClosed();
 
     // Loop over the ops that haven't yet generated their geometry
     for (int i = 0; i < fRecordedOps.count(); ++i) {