Revert 272565 "Re-land: cc: Fail more visibly when sync queries ..."

Caused two native crashes in contentshell_instrumentation_tests on
Android Tests (dbg) bot on Blink waterfall.

BUG=377053,371530,373360

> Re-land: cc: Fail more visibly when sync queries are not working correctly.
> 
> Instead of creating an infinite number of sync queries, which will
> eventually cause performance issues, log an error message and block
> until oldest query has passed when reaching 16 pending queries.
> 
> BUG=371530,373360
> 
> Review URL: https://codereview.chromium.org/280543003

TBR=reveman@chromium.org

Review URL: https://codereview.chromium.org/299923005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272638 0039d316-1c4b-4281-b951-d872f2087c98

cc/output/gl_renderer.cc

@@ -175,10 +175,6 @@ SamplerType SamplerTypeFromTextureTarget(GLenum target) {
 // determine when anti-aliasing is unnecessary.
 const float kAntiAliasingEpsilon = 1.0f / 1024.0f;
 
-// Block or crash if the number of pending sync queries reach this high as
-// something is seriously wrong on the service side if this happens.
-const size_t kMaxPendingSyncQueries = 16;
-
 }  // anonymous namespace
 
 class GLRenderer::ScopedUseGrContext {
@@ -252,11 +248,6 @@ class GLRenderer::SyncQuery {
     return !available;
   }
 
-  void Wait() {
-    unsigned result = 0;
-    gl_->GetQueryObjectuivEXT(query_id_, GL_QUERY_RESULT_EXT, &result);
-  }
-
  private:
   class Fence : public ResourceProvider::Fence {
    public:
@@ -450,15 +441,6 @@ void GLRenderer::BeginDrawingFrame(DrawingFrame* frame) {
 
   scoped_refptr<ResourceProvider::Fence> read_lock_fence;
   if (use_sync_query_) {
-    // Block until oldest sync query has passed if the number of pending queries
-    // ever reach kMaxPendingSyncQueries.
-    if (pending_sync_queries_.size() >= kMaxPendingSyncQueries) {
-      LOG(ERROR) << "Reached limit of pending sync queries.";
-
-      pending_sync_queries_.front()->Wait();
-      DCHECK(!pending_sync_queries_.front()->IsPending());
-    }
-
     while (!pending_sync_queries_.empty()) {
       if (pending_sync_queries_.front()->IsPending())
         break;