Lose context if we cannot make current

We maintain the invariant that context is current when
ScheduleGrContextCleanup is called. We mark the context
as lost if we fail MakeCurrent in PurgeGrCache.

Change-Id: Ie901056816b23d0076586f8e3bd4794c9e4e2c73
Reviewed-on: https://chromium-review.googlesource.com/c/1354120Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Jonathan Backer <backer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611900}

gpu/command_buffer/service/gr_cache_controller.cc

@@ -21,6 +21,7 @@ GrCacheController::~GrCacheController() = default;
 
 void GrCacheController::ScheduleGrContextCleanup() {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  DCHECK(context_state_->context->IsCurrent(nullptr));
 
   if (!context_state_->gr_context)
     return;
@@ -34,7 +35,6 @@ void GrCacheController::ScheduleGrContextCleanup() {
   // a long while even if it is under budget. Below we set a call back to
   // purge all possible GrContext resources if the context itself is not being
   // used.
-  context_state_->context->MakeCurrent(context_state_->surface.get());
   context_state_->gr_context->performDeferredCleanup(
       std::chrono::seconds(kOldResourceCleanupDelaySeconds));
 
@@ -50,6 +50,17 @@ void GrCacheController::ScheduleGrContextCleanup() {
 void GrCacheController::PurgeGrCache(uint64_t idle_id) {
   purge_gr_cache_cb_.Cancel();
 
+  if (context_state_->context_lost)
+    return;
+
+  // Skip unnecessary MakeCurrent to improve
+  // performance. https://crbug.com/457431
+  if (!context_state_->context->IsCurrent(nullptr) &&
+      !context_state_->context->MakeCurrent(context_state_->surface.get())) {
+    context_state_->context_lost = true;
+    return;
+  }
+
   // If the idle id changed, the context was used after this callback was
   // posted. Schedule another one.
   if (idle_id != current_idle_id_) {
@@ -57,7 +68,6 @@ void GrCacheController::PurgeGrCache(uint64_t idle_id) {
     return;
   }
 
-  context_state_->context->MakeCurrent(context_state_->surface.get());
   context_state_->gr_context->freeGpuResources();
 }