Support Coalesced Touch in ppapi

content/renderer/pepper/pepper_plugin_instance_impl.cc

Index: content/renderer/pepper/pepper_plugin_instance_impl.cc
diff --git a/content/renderer/pepper/pepper_plugin_instance_impl.cc b/content/renderer/pepper/pepper_plugin_instance_impl.cc
index 592133d4f5756491bb5a4f73d0e54de432c56972..fa9fbdc616bbe0aed066b269014a266b02a28e4f 100644
--- a/content/renderer/pepper/pepper_plugin_instance_impl.cc
+++ b/content/renderer/pepper/pepper_plugin_instance_impl.cc
@@ -97,6 +97,7 @@
 #include "printing/features/features.h"
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/public/platform/URLConversion.h"
+#include "third_party/WebKit/public/platform/WebCoalescedInputEvent.h"
 #include "third_party/WebKit/public/platform/WebCursorInfo.h"
 #include "third_party/WebKit/public/platform/WebFloatRect.h"
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
@@ -1115,6 +1116,23 @@ gfx::Rect PepperPluginInstanceImpl::GetCaretBounds() const {
   return caret;
 }
 
+bool PepperPluginInstanceImpl::HandleCoalescedInputEvent(
+    const blink::WebCoalescedInputEvent& event,
+    WebCursorInfo* cursor_info) {
+  bool result = HandleInputEvent(event.Event(), cursor_info);

[Navid Zolghadr, 2017/05/02 19:17:40]

One thing here. Note that the event itself is the accumulation of all the
coalesced events. So you either don't care about the coalesced events and only
handle this event or should only handle the coalesced events. When you tried
this didn't this make any redundant points/lines in the drawings for example?

[jkwang, 2017/05/02 22:27:04]

No, it's not a problem here. movement_x and movement_y are coalesced. But ppapi
only use the position x and position y. It is not coalesced.

[Navid Zolghadr, 2017/05/02 23:57:56]

I still see this as not something that is desired. Now you will handle at least
two points with the exact same coordinates. Is there any other reason for just
not removing this line?

[jkwang, 2017/05/03 00:36:00]

Note that the loop below is indexed from 1 instead of 0. Index 0 is the same as
event.Event(). Either way, I intend to return the result of handling the event
at index 0 (So I have to start the loop at 1).  Because it is more consistent
with previous implementation.

[Navid Zolghadr, 2017/05/03 02:30:02]

Sorry. I didn't notice that 0. That also seems incorrect. Because if I recall
correctly the last index (at least its coordinates) should match the event at
the moment with the current implementation. But you shouldn't rely on that
either. We were planning to do some resampling for the event itself and align it
with the frame time stamp and keep all the actual events happened in the
coalesced events array. Either way handling/drawing both the event and the
coalesced events at the same time is incorrect.

[jkwang, 2017/05/03 18:45:38]

Done.

+
+  if (blink::WebInputEvent::IsTouchEventType(event.Event().GetType()) &&
+      ((filtered_input_event_mask_ & PP_INPUTEVENT_CLASS_COALESCED_TOUCH) ||
+       (input_event_mask_ & PP_INPUTEVENT_CLASS_COALESCED_TOUCH))) {
+    // Handle all the Touch Events one by one. The event at index 0 is
+    // event.Event().
+    for (size_t i = 1; i < event.CoalescedEventSize(); ++i) {
+      HandleInputEvent(event.CoalescedEvent(i), cursor_info);
+    }
+  }
+  return result;
+}
+
 bool PepperPluginInstanceImpl::HandleInputEvent(
     const blink::WebInputEvent& event,
     WebCursorInfo* cursor_info) {