RenderWidget: make routing_id be a parameter of the ctor

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 b540e2bbd859026f04474b46060faac615b1f868..eca7a8df67b494ebb7f26e1ab50cd4765d7bd91f 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -209,13 +209,14 @@ namespace content {
 
 // RenderWidget ---------------------------------------------------------------
 
-RenderWidget::RenderWidget(CompositorDependencies* compositor_deps,
+RenderWidget::RenderWidget(int32_t widget_routing_id,
+                           CompositorDependencies* compositor_deps,
                            blink::WebPopupType popup_type,
                            const ScreenInfo& screen_info,
                            bool swapped_out,
                            bool hidden,
                            bool never_visible)
-    : routing_id_(MSG_ROUTING_NONE),
+    : routing_id_(widget_routing_id),
       compositor_deps_(compositor_deps),
       webwidget_internal_(nullptr),
       owner_delegate_(nullptr),
@@ -255,6 +256,7 @@ RenderWidget::RenderWidget(CompositorDependencies* compositor_deps,
       text_input_client_observer_(new TextInputClientObserver(this)),
 #endif
       focused_pepper_plugin_(nullptr) {
+  DCHECK_NE(routing_id_, MSG_ROUTING_NONE);
   if (!swapped_out)
     RenderProcess::current()->AddRefProcess();
   DCHECK(RenderThread::Get());
@@ -303,9 +305,9 @@ RenderWidget* RenderWidget::Create(int32_t opener_id,
     return nullptr;
   }
 
-  scoped_refptr<RenderWidget> widget(new RenderWidget(
-      compositor_deps, popup_type, screen_info, false, false, false));
-  widget->InitRoutingID(routing_id);
+  scoped_refptr<RenderWidget> widget(
+      new RenderWidget(routing_id, compositor_deps, popup_type, screen_info,
+                       false, false, false));
   widget->Init(opener_id, RenderWidget::CreateWebWidget(widget.get()));
   DCHECK(!widget->HasOneRef());  // RenderWidget::Init() adds a reference.
   return widget.get();
@@ -330,14 +332,15 @@ RenderWidget* RenderWidget::CreateForFrame(
   }
   scoped_refptr<RenderWidget> widget(
       g_create_render_widget
-          ? g_create_render_widget(compositor_deps, blink::WebPopupTypeNone,
-                                   screen_info, false, hidden, false)
-          : new RenderWidget(compositor_deps, blink::WebPopupTypeNone,
-                             screen_info, false, hidden, false));
+          ? g_create_render_widget(widget_routing_id, compositor_deps,
+                                   blink::WebPopupTypeNone, screen_info, false,
+                                   hidden, false)
+          : new RenderWidget(widget_routing_id, compositor_deps,
+                             blink::WebPopupTypeNone, screen_info, false,
+                             hidden, false));
   widget->for_oopif_ = true;
   // Init increments the reference count on |widget|, keeping it alive after
   // this function returns.
-  widget->InitRoutingID(widget_routing_id);
   widget->Init(MSG_ROUTING_NONE,
                RenderWidget::CreateWebFrameWidget(widget.get(), frame));
 
@@ -389,17 +392,13 @@ void RenderWidget::SetSwappedOut(bool is_swapped_out) {
     RenderProcess::current()->AddRefProcess();
 }
 
-void RenderWidget::InitRoutingID(int32_t routing_id) {
-  DCHECK_EQ(routing_id_, MSG_ROUTING_NONE);
-  routing_id_ = routing_id;
-  input_handler_.reset(new RenderWidgetInputHandler(
-      GetRenderWidgetInputHandlerDelegate(this), this));
-}
-
 void RenderWidget::Init(int32_t opener_id, WebWidget* web_widget) {
   DCHECK(!webwidget_internal_);
   DCHECK_NE(routing_id_, MSG_ROUTING_NONE);
 
+  input_handler_.reset(new RenderWidgetInputHandler(

[ncarter (slow), 2016/11/14 19:31:51]

The ordering change here is the primary source of risk I see in this CL.

For non-RenderView RenderWidgets, this is the same. But for a RenderView, the
RenderWidgetInputHandler is now being initialized after the WebWidget is
created, instead of before. I don't know of any interaction between those, but I
had assumed that input_handler_ was initialized before Init for a reason.

If this breaks tests, I can make InitRoutingID() be InitInputHandler, but I was
hoping to drop the complexity of two Init functions.

Initializing input_handler_ in the ctor breaks the
compositor_mus_connection_unittests, which never called Init and which manually
override the input_handler_. We can also fix those via more ctor dependency
injection, or an explicit factory function, or something.

+      GetRenderWidgetInputHandlerDelegate(this), this));
+
   if (opener_id != MSG_ROUTING_NONE)
     opener_id_ = opener_id;