Revert of Restructure flushing relationship between GrContext, GrDrawingManager, and GrResourceCache. (patchset #4 id:60001 of https://codereview.chromium.org/2307053002/ )

Reason for revert:
Causing assertions on bots

Original issue's description:
> Restructure flushing relationship between GrContext, GrDrawingManager, and GrResourceCache.
>
> Consolidates all flush actions into GrDrawingManager and makes GrContext::flush a passthrough.
>
> Removes the unused and untested discard flush variation.
>
> Replaces the indirect overbudget callback mechanism of GrResourceCache with a flag set by resource cache when it wants to flush that is checked after each draw by GrDrawContext.
>
> Modifies GrResourceCache::notifyFlushOccurred() to take a param indicating whether it triggered the
> flush that just occurred.
>
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2307053002
>
> Committed: https://skia.googlesource.com/skia/+/1dbb207babecdae8f1f74ed9d9900c73064df744

TBR=robertphillips@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2312123003

1 files changed, 15 insertions, 22 deletions

diff --git a/src/gpu/GrResourceCache.cpp b/src/gpu/GrResourceCache.cpp
index e3f4f9ff50..62360ed535 100644
--- a/src/gpu/GrResourceCache.cpp
+++ b/src/gpu/GrResourceCache.cpp
@@ -73,6 +73,8 @@ GrResourceCache::GrResourceCache(const GrCaps* caps)
     , fBytes(0)
     , fBudgetedCount(0)
     , fBudgetedBytes(0)
+    , fOverBudgetCB(nullptr)
+    , fOverBudgetData(nullptr)
     , fFlushTimestamps(nullptr)
     , fLastFlushTimestampIndex(0)
     , fPreferVRAMUseOverFlushes(caps->preferVRAMUseOverFlushes()) {
@@ -501,9 +503,10 @@ void GrResourceCache::purgeAsNeeded() {
     this->validate();
 
     if (stillOverbudget) {
-        // Set this so that GrDrawingManager will issue a flush to free up resources with pending
-        // IO that we were unable to purge in this pass.
-        fRequestFlush = true;
+        // Despite the purge we're still over budget. Call our over budget callback. If this frees
+        // any resources then we'll get notified and take appropriate action.
+        (*fOverBudgetCB)(fOverBudgetData);
+        this->validate();
     }
 }
 
@@ -618,26 +621,16 @@ uint32_t GrResourceCache::getNextTimestamp() {
     return fTimestamp++;
 }
 
-void GrResourceCache::notifyFlushOccurred(FlushType type) {
-    switch (type) {
-        case FlushType::kImmediateMode:
-            break;
-        case FlushType::kCacheRequested:
-            SkASSERT(fRequestFlush);
-            fRequestFlush = false;
-            break;
-        case FlushType::kExternal:
-            if (fFlushTimestamps) {
-                SkASSERT(SkIsPow2(fMaxUnusedFlushes));
-                fLastFlushTimestampIndex = (fLastFlushTimestampIndex + 1) & (fMaxUnusedFlushes - 1);
-                // get the timestamp before accessing fFlushTimestamps because getNextTimestamp will
-                // reallocate fFlushTimestamps on timestamp overflow.
-                uint32_t timestamp = this->getNextTimestamp();
-                fFlushTimestamps[fLastFlushTimestampIndex] = timestamp;
-            }
-            break;
+void GrResourceCache::notifyFlushOccurred() {
+    if (fFlushTimestamps) {
+        SkASSERT(SkIsPow2(fMaxUnusedFlushes));
+        fLastFlushTimestampIndex = (fLastFlushTimestampIndex + 1) & (fMaxUnusedFlushes - 1);
+        // get the timestamp before accessing fFlushTimestamps because getNextTimestamp will
+        // reallocate fFlushTimestamps on timestamp overflow.
+        uint32_t timestamp = this->getNextTimestamp();
+        fFlushTimestamps[fLastFlushTimestampIndex] = timestamp;
+        this->purgeAsNeeded();
     }
-    this->purgeAsNeeded();
 }
 
 void GrResourceCache::dumpMemoryStatistics(SkTraceMemoryDump* traceMemoryDump) const {