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 691149711b408195492c51dc928578823511b3f2..9d9a563ec3042fd0403b50dd2ca3d34655347910 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"
@@ -861,6 +862,13 @@ bool RenderWidgetHostViewAura::CanRendererHandleEvent(
   return true;
 }
 
+bool RenderWidgetHostViewAura::ShouldRouteEvent(const ui::Event* event) const {
+  bool result = host_->delegate() && host_->delegate()->GetInputEventRouter();
+  if (event->IsMouseEvent())

[Charlie Reis, 2015/11/30 18:09:11]

Please add a comment in this method about what policy you're trying to achieve. 
It's hard to understand what this means as is-- are we just in an intermediate
state where we use the input event router for touch but not mouse events?

Also, is this mean to affect non-BrowserPlugin code?  It looks like it affects
all views in default Chrome.

[wjmaclean, 2015/12/10 16:09:07]

Done.
It doesn't really affect all views, as in the CL only RenderWidgetHostViewAura
calls RenderWidgetHostViewBase::ProcessTouchEvent(). This means that
RenderWidgetHostView{Mac|Android} each continue to do their own thing.

At present touch forwarding is not supported in OOPIF, so this code doesn't
break anything, though it does provide a way forward in a subsequent CL.

[Charlie Reis, 2015/12/10 21:58:14]

I think you misunderstood my question.  By default Chrome, I meant platforms
that use RenderWidgetHostViewAura (i.e., Windows, Linux, and ChromeOS).  I'm
concerned that this affects behavior for Windows/Linux/ChromeOS, even for users
who don't have --site-per-process or BrowserPlugins.  It's not clear to me
whether that was intentional.

+    result = result && SiteIsolationPolicy::AreCrossProcessFramesPossible();
+  return result;
+}
+
 void RenderWidgetHostViewAura::HandleParentBoundsChanged() {
   SnapToPhysicalPixelBoundary();
 #if defined(OS_WIN)
@@ -2131,7 +2139,7 @@ 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()) {
+      if (ShouldRouteEvent(event)) {
         host_->delegate()->GetInputEventRouter()->RouteMouseWheelEvent(
             this, &mouse_wheel_event);
       } else {
@@ -2150,7 +2158,7 @@ void RenderWidgetHostViewAura::OnMouseEvent(ui::MouseEvent* event) {
 
       blink::WebMouseEvent mouse_event = MakeWebMouseEvent(*event);
       ModifyEventMovementAndCoords(&mouse_event);
-      if (host_->delegate() && host_->delegate()->GetInputEventRouter()) {
+      if (ShouldRouteEvent(event)) {
         host_->delegate()->GetInputEventRouter()->RouteMouseEvent(this,
                                                                   &mouse_event);
       } else {
@@ -2223,6 +2231,12 @@ void RenderWidgetHostViewAura::ProcessMouseWheelEvent(
   host_->ForwardWheelEvent(event);
 }
 
+void RenderWidgetHostViewAura::ProcessTouchEvent(
+    const blink::WebTouchEvent& event,
+    const ui::LatencyInfo& latency) {
+  host_->ForwardTouchEventWithLatencyInfo(event, latency);
+}
+
 void RenderWidgetHostViewAura::TransformPointToLocalCoordSpace(
     const gfx::Point& point,
     cc::SurfaceId original_surface,
@@ -2297,7 +2311,12 @@ 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 (ShouldRouteEvent(event)) {
+    host_->delegate()->GetInputEventRouter()->RouteTouchEvent(
+        this, &touch_event, *event->latency());
+  } else {
+    ProcessTouchEvent(touch_event, *event->latency());
+  }
 }
 
 void RenderWidgetHostViewAura::OnGestureEvent(ui::GestureEvent* event) {