Add Mojo API for Blink hit testing

content/renderer/input/render_widget_input_handler.cc

 // Copyright 2015 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/renderer/input/render_widget_input_handler.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <utility>
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/trace_event/trace_event_synthetic_delay.h"
 #include "build/build_config.h"
 #include "cc/trees/swap_promise_monitor.h"
 #include "content/common/input/input_event_ack.h"
 #include "content/common/input/input_event_ack_state.h"
 #include "content/public/common/content_switches.h"
+#include "content/public/renderer/render_frame.h"
 #include "content/renderer/gpu/render_widget_compositor.h"
 #include "content/renderer/ime_event_guard.h"
 #include "content/renderer/input/render_widget_input_handler_delegate.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/render_widget.h"
 #include "third_party/WebKit/public/platform/WebFloatPoint.h"
 #include "third_party/WebKit/public/platform/WebFloatSize.h"
 #include "third_party/WebKit/public/platform/WebGestureEvent.h"
 #include "third_party/WebKit/public/platform/WebKeyboardEvent.h"
 #include "third_party/WebKit/public/platform/WebMouseWheelEvent.h"
@@ skipping 169 matching lines @@
       handling_event_overscroll_(nullptr),
       handling_event_type_(WebInputEvent::kUndefined),
       suppress_next_char_events_(false) {
   DCHECK(delegate);
   DCHECK(widget);
   delegate->SetInputHandler(this);
 }
 
 RenderWidgetInputHandler::~RenderWidgetInputHandler() {}
 
+int RenderWidgetInputHandler::HitTestFrameAt(const gfx::PointF& point) {
+  return RenderFrame::GetRoutingIdForWebFrame(
+      widget_->GetWebWidget()->HitTestFrameAt(
+          blink::WebFloatPoint(point.x(), point.y())));
+}
+
 void RenderWidgetInputHandler::HandleInputEvent(
     const blink::WebCoalescedInputEvent& coalesced_event,
     const ui::LatencyInfo& latency_info,
     HandledEventCallback callback) {
   const WebInputEvent& input_event = coalesced_event.Event();
   base::AutoReset<bool> handling_input_event_resetter(&handling_input_event_,
                                                       true);
   base::AutoReset<WebInputEvent::Type> handling_event_type_resetter(
       &handling_event_type_, input_event.GetType());
 
@@ skipping 221 matching lines @@
   // it can be bundled in the event ack.
   if (handling_event_overscroll_) {
     *handling_event_overscroll_ = std::move(params);
     return;
   }
 
   delegate_->OnDidOverscroll(*params);
 }
 
 }  // namespace content