Always reset touch action at the beginning of a new gesture sequence

content/browser/renderer_host/input/input_router_impl.cc

Index: content/browser/renderer_host/input/input_router_impl.cc
diff --git a/content/browser/renderer_host/input/input_router_impl.cc b/content/browser/renderer_host/input/input_router_impl.cc
index b303acdb94cb21899d3042796cce2fe0c561ca98..fe5e4dc60fd995d389d0fd2e278ef1fff6c09fff 100644
--- a/content/browser/renderer_host/input/input_router_impl.cc
+++ b/content/browser/renderer_host/input/input_router_impl.cc
@@ -13,11 +13,11 @@
 #include "content/browser/renderer_host/input/input_router_client.h"
 #include "content/browser/renderer_host/input/touch_event_queue.h"
 #include "content/browser/renderer_host/input/touchpad_tap_suppression_controller.h"
+#include "content/browser/renderer_host/input/web_touch_event_traits.h"
 #include "content/browser/renderer_host/overscroll_controller.h"
 #include "content/common/content_constants_internal.h"
 #include "content/common/edit_command.h"
 #include "content/common/input/touch_action.h"
-#include "content/common/input/web_input_event_traits.h"
 #include "content/common/input_messages.h"
 #include "content/common/view_messages.h"
 #include "content/port/common/input_event_ack_state.h"
@@ -286,6 +286,9 @@ void InputRouterImpl::SendMouseEventImmediately(
 
 void InputRouterImpl::SendTouchEventImmediately(
     const TouchEventWithLatencyInfo& touch_event) {
+  if (WebTouchEventTraits::IsTouchSequenceStart(touch_event.event))
+    touch_action_filter_.OnTouchSequenceStart();
+
   FilterAndSendWebInputEvent(touch_event.event, touch_event.latency, false);
 }
 
@@ -335,6 +338,12 @@ bool InputRouterImpl::OnMessageReceived(const IPC::Message& message) {
 
 void InputRouterImpl::OnTouchEventAck(const TouchEventWithLatencyInfo& event,
                                       InputEventAckState ack_result) {
+  // Touchstart events sent to the renderer indicate a new touch sequence, but
+  // in some cases we may filter out sending the touchstart - catch those here.
+  if (event.event.type == WebInputEvent::TouchStart &&

[jdduke (slow), 2014/02/26 15:40:55]

Shouldn't this be |IsTouchSequenceStart()|?

[tdresser, 2014/02/26 19:31:27]

Done.

+      ack_result == INPUT_EVENT_ACK_STATE_NO_CONSUMER_EXISTS) {
+    touch_action_filter_.OnTouchSequenceStart();

[jdduke (slow), 2014/02/26 15:40:55]

Can we rename |OnTouchSequenceStart()| to something like |ResetTouchAction()|?
That way it's immediately obvious what this call is doing, and we don't have to
hijack the method for a case like this.

[tdresser, 2014/02/26 19:31:27]

Done.

+  }
   ack_handler_->OnTouchEventAck(event, ack_result);
 }