Delete RenderView after RenderWidget destructor.

This changes the deletion order of RenderView and RenderWidget.
From analysis, it seems the two pieces of code should be independent.

Bug: 545684
Change-Id: I470c390eb7c3e51a6868fa758f76718c3d1cdcf7
Reviewed-on: https://chromium-review.googlesource.com/c/1387747Reviewed-by: Albert J. Wong <ajwong@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Commit-Queue: Albert J. Wong <ajwong@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618390}

content/renderer/render_widget.cc

@@ -442,12 +442,6 @@ RenderWidget::RenderWidget(int32_t widget_routing_id,
 RenderWidget::~RenderWidget() {
   DCHECK(!webwidget_internal_) << "Leaking our WebWidget!";
 
-  // TODO(ajwong): Test if this actually has to be reset here
-  // or if it is okay to tear down later in the destructor. This
-  // would allow for removing the ordering constraint in teardown.
-  // https://crbug.com/545684
-  delegate_.reset();
-
   // TODO(ajwong): Add in check that routing_id_ has been removed from
   // g_routing_id_widget_map once the shutdown semantics for RenderWidget
   // and RenderViewImpl are rationalized. Currently, too many unit and