Pass MotionEvent tilt angles to Blink on Android.

content/browser/renderer_host/input/motion_event_web.cc

 // Copyright 2014 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.
 
 // MSVC++ requires this to be set before any other includes to get M_PI.
 #define _USE_MATH_DEFINES
 
 #include "content/browser/renderer_host/input/motion_event_web.h"
 
 #include <cmath>
@@ skipping 131 matching lines @@
     rotation_angle_rad -= (float) M_PI_2;
   }
 
   return rotation_angle_rad;
 }
 
 float MotionEventWeb::GetPressure(size_t pointer_index) const {
   return 0.f;
 }
 
+float MotionEventWeb::GetTilt(size_t pointer_index) const {
+  return 0.f;

[jdduke (slow), 2015/07/31 15:00:49]

Hmm, can't we get this value from the WebTouchEvent?

[USE eero AT chromium.org, 2015/07/31 18:18:15]

Yes, although it is a bit complex. Also this member function will not be called
yet as the GetToolType member function does not return real tool type yet (but
only after https://crrev.com/1190013002/). But let's implement this now, thus
done.

+}
+
 base::TimeTicks MotionEventWeb::GetEventTime() const {
   return base::TimeTicks() +
          base::TimeDelta::FromMicroseconds(event_.timeStampSeconds *
                                            base::Time::kMicrosecondsPerSecond);
 }
 
 ui::MotionEvent::ToolType MotionEventWeb::GetToolType(
     size_t pointer_index) const {
   // TODO(jdduke): Plumb tool type from the platform event, crbug.com/404128.
   DCHECK_LT(pointer_index, GetPointerCount());
   return TOOL_TYPE_UNKNOWN;
 }
 
 int MotionEventWeb::GetButtonState() const {
   return 0;
 }
 
 int MotionEventWeb::GetFlags() const {
   return WebEventModifiersToEventFlags(event_.modifiers);
 }
 
 }  // namespace content