Implementation of device metrics emulation in render view.

content/renderer/gpu/input_handler_manager.cc

Index: content/renderer/gpu/input_handler_manager.cc
===================================================================
--- content/renderer/gpu/input_handler_manager.cc	(revision 221161)
+++ content/renderer/gpu/input_handler_manager.cc	(working copy)
@@ -93,6 +93,25 @@
           routing_id, main_loop, input_handler, render_view_impl));
 }
 
+void InputHandlerManager::SetInputEventRewriter(
+    int routing_id,
+    scoped_ptr<InputEventRewriter> rewriter) {
+  message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&InputHandlerManager::SetInputEventRewriterOnCompositorThread,
+                 base::Unretained(this),
+                 routing_id,
+                 base::Passed(&rewriter)));
+}
+
+void InputHandlerManager::SetInputEventRewriterOnCompositorThread(
+    int routing_id,
+    scoped_ptr<InputEventRewriter> rewriter) {
+  InputHandlerMap::iterator it = input_handlers_.find(routing_id);
+  if (it != input_handlers_.end())
+    it->second->SetRewriter(rewriter.Pass());
+}
+
 void InputHandlerManager::RemoveInputHandler(int routing_id) {
   DCHECK(message_loop_proxy_->BelongsToCurrentThread());
 
@@ -116,6 +135,16 @@
     return INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
   }
 
+  scoped_ptr<WebInputEvent> rewritten_event_owner;
+  InputEventRewriter* rewriter = it->second->rewriter();
+  if (rewriter) {
+    WebInputEvent* rewritten = rewriter->RewriteInputEvent(input_event);
+    if (rewritten) {
+      rewritten_event_owner.reset(rewritten);
+      input_event = rewritten;
+    }
+  }
+
   InputHandlerProxy* proxy = it->second->input_handler_proxy();
   return InputEventDispositionToAck(
       proxy->HandleInputEventWithLatencyInfo(*input_event, latency_info));