Prepare SyntheticPointerAction to handle touch actions for multiple fingers

content/browser/renderer_host/input/synthetic_gesture_target_base.cc

 // Copyright 2013 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/input/synthetic_gesture_target_base.h"
 
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/browser/renderer_host/ui_events_helper.h"
 #include "content/common/input_messages.h"
@@ skipping 37 matching lines @@
                "type", WebInputEventTraits::GetName(event.type));
 
   ui::LatencyInfo latency_info;
   latency_info.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
 
   if (WebInputEvent::isTouchEventType(event.type)) {
     const WebTouchEvent& web_touch =
         static_cast<const WebTouchEvent&>(event);
 
     // Check that all touch pointers are within the content bounds.
-    if (web_touch.type == WebInputEvent::TouchStart) {
-      for (unsigned i = 0; i < web_touch.touchesLength; i++)
-        CHECK(web_touch.touches[i].state != WebTouchPoint::StatePressed ||
-              PointIsWithinContents(web_touch.touches[i].position.x,
-                                    web_touch.touches[i].position.y))
-            << "Touch coordinates are not within content bounds on TouchStart.";
-    }
+    for (unsigned i = 0; i < web_touch.touchesLength; i++)
+      CHECK(web_touch.touches[i].state != WebTouchPoint::StatePressed ||
+            PointIsWithinContents(web_touch.touches[i].position.x,
+                                  web_touch.touches[i].position.y))
+          << "Touch coordinates are not within content bounds on TouchStart.";

[tdresser, 2016/05/13 13:58:04]

Is dragging your finger outside the window reasonable?

Also, the log text still references TouchStart.

[lanwei, 2016/05/19 16:04:13]

Because when we combine actions together, sometimes touch event's type is not
TouchStart, but it may have a touch point which is a press, so I need to check
for all the touch points' state. 

 
     DispatchWebTouchEventToPlatform(web_touch, latency_info);
   } else if (event.type == WebInputEvent::MouseWheel) {
     const WebMouseWheelEvent& web_wheel =
         static_cast<const WebMouseWheelEvent&>(event);
     CHECK(PointIsWithinContents(web_wheel.x, web_wheel.y))
         << "Mouse wheel position is not within content bounds.";
     DispatchWebMouseWheelEventToPlatform(web_wheel, latency_info);
   } else if (WebInputEvent::isMouseEventType(event.type)) {
     const WebMouseEvent& web_mouse =
@@ skipping 53 matching lines @@
   return 0.0f;
 }
 
 bool SyntheticGestureTargetBase::PointIsWithinContents(int x, int y) const {
   gfx::Rect bounds = host_->GetView()->GetViewBounds();
   bounds -= bounds.OffsetFromOrigin();  // Translate the bounds to (0,0).
   return bounds.Contains(x, y);
 }
 
 }  // namespace content