Revert of Discard compositor frames from unloaded web content

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 6a4442fa9cb31bf7e7676f129c07fdb42836a797..f5f43f07028bb43d883919571d84b0d52a50c28c 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -378,7 +378,6 @@
       focused_pepper_plugin_(nullptr),
       time_to_first_active_paint_recorded_(true),
       was_shown_time_(base::TimeTicks::Now()),
-      current_content_source_id_(0),
       weak_ptr_factory_(this) {
   DCHECK_NE(routing_id_, MSG_ROUTING_NONE);
   if (!swapped_out)
@@ -1287,7 +1286,6 @@
   compositor_->setViewportSize(physical_backing_size_);
   OnDeviceScaleFactorChanged();
   compositor_->SetDeviceColorSpace(screen_info_.icc_profile.GetColorSpace());
-  compositor_->SetContentSourceId(current_content_source_id_);
   // For background pages and certain tests, we don't want to trigger
   // CompositorFrameSink creation.
   if (compositor_never_visible_ || !RenderThreadImpl::current())
@@ -2302,15 +2300,6 @@
                                      possible_drag_event_info_));
 }
 
-uint32_t RenderWidget::GetContentSourceId() {
-  return current_content_source_id_;
-}
-
-void RenderWidget::IncrementContentSourceId() {
-  if (compositor_)
-    compositor_->SetContentSourceId(++current_content_source_id_);
-}
-
 blink::WebWidget* RenderWidget::GetWebWidget() const {
   return webwidget_internal_;
 }