Throttle the touch move events sent to the renderer.

content/browser/renderer_host/render_widget_host.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/i18n/rtl.h"
@@ skipping 57 matching lines @@
       view_(NULL),
       process_(process),
       routing_id_(routing_id),
       is_loading_(false),
       is_hidden_(false),
       is_accelerated_compositing_active_(false),
       repaint_ack_pending_(false),
       resize_ack_pending_(false),
       mouse_move_pending_(false),
       mouse_wheel_pending_(false),
+#if defined(TOUCH_UI)
+      touch_move_pending_(false),
+      touch_event_is_queued_(false),
+#endif
       needs_repainting_on_restore_(false),
       is_unresponsive_(false),
       in_get_backing_store_(false),
       view_being_painted_(false),
       ignore_input_events_(false),
       text_direction_updated_(false),
       text_direction_(WebKit::WebTextDirectionLeftToRight),
       text_direction_canceled_(false),
       suppress_next_char_events_(false) {
   if (routing_id_ == MSG_ROUTING_NONE)
@@ skipping 548 matching lines @@
     coalesced_mouse_wheel_events_.clear();
 
   // Any input event cancels a pending mouse move event. Note that
   // |next_mouse_move_| possibly owns |input_event|, so don't use |input_event|
   // after this line.
   next_mouse_move_.reset();
 
   StartHangMonitorTimeout(TimeDelta::FromMilliseconds(kHungRendererDelayMs));
 }
 
 #if defined(TOUCH_UI)

[sky, 2011/06/09 21:58:12]

De we need the ifdefs? If you're not on a touch device will we get any of these
events?

[sadrul, 2011/06/09 22:15:45]

ifdef's removed!

 void RenderWidgetHost::ForwardTouchEvent(
     const WebKit::WebTouchEvent& touch_event) {
   TRACE_EVENT0("renderer_host", "RenderWidgetHost::ForwardTouchEvent");
+  if (ignore_input_events_ || process_->ignore_input_events())
+    return;
+
+  if (touch_event.type == WebInputEvent::TouchMove &&
+      touch_move_pending_) {
+    touch_event_is_queued_ = true;
+    queued_touch_event_ = touch_event;
+    return;
+  }
+
+  if (touch_event.type == WebInputEvent::TouchMove)
+    touch_move_pending_ = true;
+  else
+    touch_move_pending_ = false;
   ForwardInputEvent(touch_event, sizeof(WebKit::WebTouchEvent), false);
 }
 #endif
 
 void RenderWidgetHost::RendererExited(base::TerminationStatus status,
                                       int exit_code) {
   // Clearing this flag causes us to re-create the renderer when recovering
   // from a crashed renderer.
   renderer_initialized_ = false;
 
   // Must reset these to ensure that mouse move/wheel events work with a new
   // renderer.
   mouse_move_pending_ = false;
   next_mouse_move_.reset();
   mouse_wheel_pending_ = false;
   coalesced_mouse_wheel_events_.clear();
 
+#if defined(TOUCH_UI)
+  touch_move_pending_ = false;
+  touch_event_is_queued_ = false;
+#endif
+
   // Must reset these to ensure that keyboard events work with a new renderer.
   key_queue_.clear();
   suppress_next_char_events_ = false;
 
   // Reset some fields in preparation for recovering from a crash.
   resize_ack_pending_ = false;
   repaint_ack_pending_ = false;
 
   in_flight_size_.SetSize(0, 0);
   in_flight_reserved_rect_.SetRect(0, 0, 0, 0);
@@ skipping 308 matching lines @@
   } else if (type == WebInputEvent::MouseWheel) {
     ProcessWheelAck();
   } else if (WebInputEvent::isKeyboardEventType(type)) {
     bool processed = false;
     if (!message.ReadBool(&iter, &processed)) {
       UserMetrics::RecordAction(UserMetricsAction("BadMessageTerminate_RWH3"));
       process()->ReceivedBadMessage();
     }
 
     ProcessKeyboardEventAck(type, processed);
+#if defined(TOUCH_UI)
+  } else if (type == WebInputEvent::TouchMove) {
+    touch_move_pending_ = false;
+    if (touch_event_is_queued_) {
+      touch_event_is_queued_ = false;
+      ForwardTouchEvent(queued_touch_event_);
+    }
+#endif
   }
   // This is used only for testing.
   NotificationService::current()->Notify(
       NotificationType::RENDER_WIDGET_HOST_DID_RECEIVE_INPUT_EVENT_ACK,
       Source<RenderWidgetHost>(this),
       Details<int>(&type));
 }
 
 void RenderWidgetHost::ProcessWheelAck() {
   mouse_wheel_pending_ = false;
@@ skipping 172 matching lines @@
     view_->CreatePluginContainer(deferred_plugin_handles_[i]);
 #endif
   }
 
   deferred_plugin_handles_.clear();
 }
 
 void RenderWidgetHost::StartUserGesture() {
   OnUserGesture();
 }