Route touch-events for WebViewGuest directly to guest renderer.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index bbb79c967405304c7bb46b1823dfea04d09bf7f0..afb4140d315b3badf167bf2525c51d028c46b23d 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -44,6 +44,7 @@
 #include "content/browser/renderer_host/web_input_event_aura.h"
 #include "content/common/gpu/client/gl_helper.h"
 #include "content/common/gpu/gpu_messages.h"
+#include "content/common/site_isolation_policy.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/overscroll_configuration.h"
@@ -450,6 +451,7 @@ RenderWidgetHostViewAura::RenderWidgetHostViewAura(RenderWidgetHost* host,
     : host_(RenderWidgetHostImpl::From(host)),
       window_(new aura::Window(this)),
       delegated_frame_host_(new DelegatedFrameHost(this)),
+      has_started_rendering_(false),
       in_shutdown_(false),
       in_bounds_changed_(false),
       is_fullscreen_(false),
@@ -487,14 +489,6 @@ RenderWidgetHostViewAura::RenderWidgetHostViewAura(RenderWidgetHost* host,
   window_->set_layer_owner_delegate(delegated_frame_host_.get());
   gfx::Screen::GetScreenFor(window_)->AddObserver(this);
 
-  // Let the page-level input event router know about our surface ID
-  // namespace for surface-based hit testing.
-  if (UseSurfacesEnabled() && host_->delegate() &&
-      host_->delegate()->GetInputEventRouter()) {
-    host_->delegate()->GetInputEventRouter()->AddSurfaceIdNamespaceOwner(
-        GetSurfaceIdNamespace(), this);
-  }
-
   bool overscroll_enabled = base::CommandLine::ForCurrentProcess()->
       GetSwitchValueASCII(switches::kOverscrollHistoryNavigation) != "0";
   SetOverscrollControllerEnabled(overscroll_enabled);
@@ -1176,6 +1170,18 @@ void RenderWidgetHostViewAura::OnSwapCompositorFrame(
   last_scroll_offset_ = frame->metadata.root_scroll_offset;
   if (!frame->delegated_frame_data)
     return;
+
+  if (!has_started_rendering_) {
+    // Let the page-level input event router know about our surface ID
+    // namespace for surface-based hit testing.
+    if (UseSurfacesEnabled() && host_->delegate() &&
+        host_->delegate()->GetInputEventRouter()) {
+      host_->delegate()->GetInputEventRouter()->AddSurfaceIdNamespaceOwner(
+          GetSurfaceIdNamespace(), this);
+    }
+    has_started_rendering_ = true;
+  }
+
   delegated_frame_host_->SwapDelegatedFrame(
       output_surface_id, frame->delegated_frame_data.Pass(),
       frame->metadata.device_scale_factor, frame->metadata.latency_info,
@@ -2110,7 +2116,12 @@ void RenderWidgetHostViewAura::OnMouseEvent(ui::MouseEvent* event) {
     blink::WebMouseWheelEvent mouse_wheel_event =
         MakeWebMouseWheelEvent(static_cast<ui::MouseWheelEvent&>(*event));
     if (mouse_wheel_event.deltaX != 0 || mouse_wheel_event.deltaY != 0) {
-      if (host_->delegate() && host_->delegate()->GetInputEventRouter()) {
+      // TODO(wjmaclean); if AreCrossProcessFramesPossible() returns true,
+      // can we safely assume that any existing delegate will have an
+      // InputEventRouter? Also, is the call to AreCrossProcessFramesPossible()
+      // expensive? If so, can the result be stored in a bool?

[kenrb, 2015/11/02 16:04:22]

I don't think we can assume a non-null return from GetInputEventRouter() because
interstitial pages don't create one and they do implement
RenderWidgetHostDelegate.

[wjmaclean, 2015/11/02 19:23:10]

Ok, good to know.

+      if (SiteIsolationPolicy::AreCrossProcessFramesPossible() &&
+          host_->delegate() && host_->delegate()->GetInputEventRouter()) {
         host_->delegate()->GetInputEventRouter()->RouteMouseWheelEvent(
             this, &mouse_wheel_event);

[tdresser, 2015/11/02 15:38:25]

Could we refactor this into
ShouldRouteEvent and RouteEvent methods, or something like that?

There's a bunch of duplication here, that makes this a bit harder to read.

[wjmaclean, 2015/11/02 19:23:10]

ShouldRouteEvent() was fairly easy, since we can key it off ui::Event*, but a
single RouteEvent() method would be quite a bit messier ... on account of the
different signatures, creating WebInputEvent types, etc. 

Is this version better?

[tdresser, 2015/11/02 21:10:19]

This looks good to me.

       } else {
@@ -2129,7 +2140,9 @@ void RenderWidgetHostViewAura::OnMouseEvent(ui::MouseEvent* event) {
 
       blink::WebMouseEvent mouse_event = MakeWebMouseEvent(*event);
       ModifyEventMovementAndCoords(&mouse_event);
-      if (host_->delegate() && host_->delegate()->GetInputEventRouter()) {
+      // TODO(wjmaclean): ditto the TODO above.
+      if (SiteIsolationPolicy::AreCrossProcessFramesPossible() &&
+          host_->delegate() && host_->delegate()->GetInputEventRouter()) {
         host_->delegate()->GetInputEventRouter()->RouteMouseEvent(this,
                                                                   &mouse_event);
       } else {
@@ -2193,6 +2206,12 @@ void RenderWidgetHostViewAura::ProcessMouseWheelEvent(
   host_->ForwardWheelEvent(event);
 }
 
+void RenderWidgetHostViewAura::ProcessTouchEvent(
+    const blink::WebTouchEvent& event,
+    const ui::LatencyInfo& latency) {
+  host_->ForwardTouchEventWithLatencyInfo(event, latency);
+}
+
 void RenderWidgetHostViewAura::OnScrollEvent(ui::ScrollEvent* event) {
   TRACE_EVENT0("input", "RenderWidgetHostViewAura::OnScrollEvent");
 
@@ -2259,7 +2278,12 @@ void RenderWidgetHostViewAura::OnTouchEvent(ui::TouchEvent* event) {
   // Set unchanged touch point to StateStationary for touchmove and
   // touchcancel to make sure only send one ack per WebTouchEvent.
   MarkUnchangedTouchPointsAsStationary(&touch_event, event->touch_id());
-  host_->ForwardTouchEventWithLatencyInfo(touch_event, *event->latency());
+  if (host_->delegate() && host_->delegate()->GetInputEventRouter()) {
+    host_->delegate()->GetInputEventRouter()->RouteTouchEvent(
+        this, &touch_event, *event->latency());
+  } else {
+    ProcessTouchEvent(touch_event, *event->latency());
+  }
 }
 
 void RenderWidgetHostViewAura::OnGestureEvent(ui::GestureEvent* event) {