Bundle main thread overscroll data with event ack messages
Currently, every main thread overscroll event will trigger an overscroll
IPC notification. However, most such events occur in the context of
handling input events. For such cases, bundle the overscroll data with
the event ack.
BUG=442859,502146
Review URL: https://codereview.chromium.org/1209043002
Cr-Commit-Position: refs/heads/master@{#336293}
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index d1faa542..de160162 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -491,6 +491,7 @@
display_mode_(blink::WebDisplayModeUndefined),
has_focus_(false),
handling_input_event_(false),
+ handling_event_overscroll_(nullptr),
handling_ime_event_(false),
handling_event_type_(WebInputEvent::Undefined),
ignore_ack_for_mouse_move_from_debugger_(false),
@@ -1067,12 +1068,20 @@
void RenderWidget::OnHandleInputEvent(const blink::WebInputEvent* input_event,
const ui::LatencyInfo& latency_info,
bool is_keyboard_shortcut) {
- base::AutoReset<bool> handling_input_event_resetter(
- &handling_input_event_, true);
if (!input_event)
return;
+ base::AutoReset<bool> handling_input_event_resetter(&handling_input_event_,
+ true);
base::AutoReset<WebInputEvent::Type> handling_event_type_resetter(
&handling_event_type_, input_event->type);
+
+ // Calls into |didOverscroll()| while handling this event will populate
+ // |event_overscroll|, which in turn will be bundled with the event ack.
+ scoped_ptr<DidOverscrollParams> event_overscroll;
+ base::AutoReset<scoped_ptr<DidOverscrollParams>*>
+ handling_event_overscroll_resetter(&handling_event_overscroll_,
+ &event_overscroll);
+
#if defined(OS_ANDROID)
// On Android, when a key is pressed or sent from the Keyboard using IME,
// |AdapterInputConnection| generates input key events to make sure all JS
@@ -1226,6 +1235,7 @@
if (WebInputEventTraits::WillReceiveAckFromRenderer(*input_event) &&
!no_ack) {
InputEventAck ack(input_event->type, ack_result, swap_latency_info,
+ event_overscroll.Pass(),
WebInputEventTraits::GetUniqueTouchEventId(*input_event));
scoped_ptr<IPC::Message> response(
new InputHostMsg_HandleInputEvent_ACK(routing_id_, ack));
@@ -1251,6 +1261,8 @@
} else {
Send(response.release());
}
+ } else {
+ DCHECK(!event_overscroll) << "Unexpected overscroll for un-acked event";
}
if (!no_ack && RenderThreadImpl::current()) {
RenderThreadImpl::current()
@@ -2221,8 +2233,6 @@
const blink::WebFloatPoint& position,
const blink::WebFloatSize& velocity) {
DidOverscrollParams params;
- // TODO(jdduke): Consider bundling the overscroll with the input event ack to
- // save an IPC.
params.accumulated_overscroll = gfx::Vector2dF(
accumulatedRootOverScroll.width, accumulatedRootOverScroll.height);
params.latest_overscroll_delta =
@@ -2232,6 +2242,14 @@
params.current_fling_velocity =
gfx::Vector2dF(-velocity.width, -velocity.height);
params.causal_event_viewport_point = gfx::PointF(position.x, position.y);
+
+ // If we're currently handling an event, stash the overscroll data such that
+ // it can be bundled in the event ack.
+ if (handling_event_overscroll_) {
+ handling_event_overscroll_->reset(new DidOverscrollParams(params));
+ return;
+ }
+
Send(new InputHostMsg_DidOverscroll(routing_id_, params));
}
