Remove ShallowFlushCHROMIUM after resource deletion

I unintentionally added this to an unrelated CL, didn't mean to commit.

R=vmpstr,reveman
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2625033003
Cr-Commit-Position: refs/heads/master@{#443011}

cc/resources/resource_provider.cc

@@ -824,9 +824,6 @@ void ResourceProvider::DeleteResourceInternal(ResourceMap::iterator it,
     DCHECK(gl);
     gl->DeleteTextures(1, &resource->gl_id);
     resource->gl_id = 0;
-    // Shallow flush after deleting a texture to make sure the memory is freed
-    // as soon as possible.
-    gl->ShallowFlushCHROMIUM();
   }
   if (resource->shared_bitmap) {
     DCHECK(resource->origin != Resource::EXTERNAL);