Overhaul Mandoline event transport code

components/html_viewer/blink_input_events_type_converters.cc

Index: components/html_viewer/blink_input_events_type_converters.cc
diff --git a/components/html_viewer/blink_input_events_type_converters.cc b/components/html_viewer/blink_input_events_type_converters.cc
index 0e8b1d67fbf74861e3b229ed23447b59591195d4..50e7dae1913fcdbf9e3dc32419757bab23c80424 100644
--- a/components/html_viewer/blink_input_events_type_converters.cc
+++ b/components/html_viewer/blink_input_events_type_converters.cc
@@ -147,19 +147,41 @@ scoped_ptr<blink::WebInputEvent> BuildWebMouseWheelEventFrom(
 
   SetWebMouseEventLocation(*(event->pointer_data), web_event.get());
 
-  if ((event->flags & mojo::EVENT_FLAGS_SHIFT_DOWN) != 0 &&
-      event->pointer_data->horizontal_wheel == 0) {
-    web_event->deltaX = event->pointer_data->horizontal_wheel;
-    web_event->deltaY = 0;
-  } else {
-    web_event->deltaX = event->pointer_data->horizontal_wheel;
-    web_event->deltaY = event->pointer_data->vertical_wheel;
-  }
+  // TODO(rjkroege): Update the following code once Blink supports
+  // DOM Level 3 wheel events
+  // (http://www.w3.org/TR/DOM-Level-3-Events/#events-wheelevents)
+  web_event->deltaX = event->pointer_data->wheel_data->delta_x;
+  web_event->deltaY = event->pointer_data->wheel_data->delta_y;
 
-  // TODO(sky): resole this, doesn't work for desktop.
   web_event->wheelTicksX = web_event->deltaX / kPixelsPerTick;
   web_event->wheelTicksY = web_event->deltaY / kPixelsPerTick;
 
+  // TODO(rjkroege): Mandoline currently only generates WHEEL_MODE_LINE
+  // wheel events so the other modes are not yet tested. Verify that
+  // the implementation is correct.
+  switch (event->pointer_data->wheel_data->mode) {
+    case mojo::WHEEL_MODE_PIXEL:
+      web_event->hasPreciseScrollingDeltas = true;
+      web_event->scrollByPage = false;
+      web_event->canScroll = true;
+      break;
+    case mojo::WHEEL_MODE_LINE:
+      web_event->hasPreciseScrollingDeltas = false;
+      web_event->scrollByPage = false;
+      web_event->canScroll = true;
+      break;
+    case mojo::WHEEL_MODE_PAGE:
+      web_event->hasPreciseScrollingDeltas = false;
+      web_event->scrollByPage = true;
+      web_event->canScroll = true;
+      break;
+    case mojo::WHEEL_MODE_SCALING:
+      web_event->hasPreciseScrollingDeltas = false;
+      web_event->scrollByPage = false;
+      web_event->canScroll = false;
+      break;
+  }
+
   return web_event.Pass();
 }
 
@@ -173,8 +195,7 @@ TypeConverter<scoped_ptr<blink::WebInputEvent>, EventPtr>::Convert(
       event->action == mojo::EVENT_TYPE_POINTER_UP ||
       event->action == mojo::EVENT_TYPE_POINTER_CANCEL ||
       event->action == mojo::EVENT_TYPE_POINTER_MOVE) {
-    if (event->pointer_data->horizontal_wheel != 0 ||
-        event->pointer_data->vertical_wheel != 0) {
+    if (event->pointer_data->kind == mojo::POINTER_KIND_WHEEL) {
       return BuildWebMouseWheelEventFrom(event);
     }
     if (event->pointer_data->kind == mojo::POINTER_KIND_MOUSE)