[Android] Perform haptic feedback after long press when appropriate

content/browser/renderer_host/input/touch_selection_controller.cc

Index: content/browser/renderer_host/input/touch_selection_controller.cc
diff --git a/content/browser/renderer_host/input/touch_selection_controller.cc b/content/browser/renderer_host/input/touch_selection_controller.cc
index 8193fb180668397e589d451edf2f107e782af49a..352bf364c964b7c76fe864089b77589351364569 100644
--- a/content/browser/renderer_host/input/touch_selection_controller.cc
+++ b/content/browser/renderer_host/input/touch_selection_controller.cc
@@ -183,6 +183,8 @@ bool TouchSelectionController::Animate(base::TimeTicks frame_time) {
 }
 
 void TouchSelectionController::OnHandleDragBegin(const TouchHandle& handle) {
+  last_input_event_type_ = INPUT_EVENT_TYPE_NONE;
+
   if (&handle == insertion_handle_.get()) {
     client_->OnSelectionEvent(INSERTION_DRAG_STARTED, handle.position());
     return;
@@ -324,8 +326,12 @@ void TouchSelectionController::ActivateSelection() {
     end_selection_handle_->SetOrientation(end_orientation_);
   }
 
-  if (!is_selection_active_) {
+  // As a long press received while a selection is already active may trigger
+  // an entirely new selection, notify the client but avoid sending an
+  // intervening SELECTION_CLEARED update to avoid unnecessary state changes.
+  if (!is_selection_active_ || last_input_event_type_ == LONG_PRESS) {

[cjhopman, 2014/08/14 00:12:28]

Maybe there's a better name for last_input_event_type_, maybe
pending_input_event_type_ or response_pending_input_event_type_. 

Should this be reset to NONE on other events that might signify that it is done?


Should we have a more robust way of determining that a particular event (or type
of event) caused a selection change?

[jdduke (slow), 2014/08/14 17:57:19]

Yeah, I'll tweak it.
Yes.
Yeah, the current attempt is both lazy and imprecise.  I've put in a hard reset
of the event any time the selection changes.  That still doesn't guarantee the
change came from a gesture; that would probably involve wiring the causal change
from Blink to be truly accurate.

     is_selection_active_ = true;
+    last_input_event_type_ = INPUT_EVENT_TYPE_NONE;
     client_->OnSelectionEvent(SELECTION_SHOWN, GetStartPosition());
   }
 }