NOT FOR REVIEW: Adding prioritized incoming task queue to renderers

content/renderer/input/input_event_filter.cc

Index: content/renderer/input/input_event_filter.cc
diff --git a/content/renderer/input/input_event_filter.cc b/content/renderer/input/input_event_filter.cc
index cd5a8cd36c7b383a3145b213c1745c33ef68a3c7..6d9883234a7c8cf4dcb906551dfc48145be5d94d 100644
--- a/content/renderer/input/input_event_filter.cc
+++ b/content/renderer/input/input_event_filter.cc
@@ -8,6 +8,7 @@
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/location.h"
+#include "base/message_loop/high_priority_task_runner.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "cc/input/input_handler.h"
 #include "content/common/input/did_overscroll_params.h"
@@ -134,14 +135,25 @@ void InputEventFilter::ForwardToHandler(const IPC::Message& message) {
                "message_type", GetInputMessageTypeName(message));
 
   if (message.type() != InputMsg_HandleInputEvent::ID) {
-    TRACE_EVENT_INSTANT0(
-        "input",
-        "InputEventFilter::ForwardToHandler::ForwardToMainListener",
-        TRACE_EVENT_SCOPE_THREAD);
-    main_loop_->PostTask(
-        FROM_HERE,
-        base::Bind(&InputEventFilter::ForwardToMainListener,
-                   this, message));
+    if (high_priority_task_runner_.get()) {
+      TRACE_EVENT_INSTANT0(
+          "input",
+          "InputEventFilter::ForwardToHandler::ForwardToMainListenerHigh",
+          TRACE_EVENT_SCOPE_THREAD);
+     high_priority_task_runner_->PostTask(
+          FROM_HERE,
+          base::Bind(&InputEventFilter::ForwardToMainListener,
+                     this, message));
+    } else {
+      TRACE_EVENT_INSTANT0(
+          "input",
+          "InputEventFilter::ForwardToHandler::ForwardToMainListener",
+          TRACE_EVENT_SCOPE_THREAD);
+      main_loop_->PostTask(
+          FROM_HERE,
+          base::Bind(&InputEventFilter::ForwardToMainListener,
+                     this, message));
+    }
     return;
   }
 
@@ -157,16 +169,27 @@ void InputEventFilter::ForwardToHandler(const IPC::Message& message) {
   InputEventAckState ack = handler_.Run(routing_id, event, &latency_info);
 
   if (ack == INPUT_EVENT_ACK_STATE_NOT_CONSUMED) {
-    TRACE_EVENT_INSTANT0(
-        "input",
-        "InputEventFilter::ForwardToHandler::ForwardToMainListener",
-        TRACE_EVENT_SCOPE_THREAD);
     IPC::Message new_msg = InputMsg_HandleInputEvent(
         routing_id, event, latency_info, is_keyboard_shortcut);
-    main_loop_->PostTask(
-        FROM_HERE,
-        base::Bind(&InputEventFilter::ForwardToMainListener,
-                   this, new_msg));
+    if (high_priority_task_runner_.get()) {
+      TRACE_EVENT_INSTANT0(
+          "input",
+          "InputEventFilter::ForwardToHandler::ForwardToMainListenerHigh",
+          TRACE_EVENT_SCOPE_THREAD);
+      high_priority_task_runner_->PostTask(
+          FROM_HERE,
+          base::Bind(&InputEventFilter::ForwardToMainListener,
+                     this, new_msg));
+    } else {
+      TRACE_EVENT_INSTANT0(
+          "input",
+          "InputEventFilter::ForwardToHandler::ForwardToMainListener",
+          TRACE_EVENT_SCOPE_THREAD);
+      main_loop_->PostTask(
+          FROM_HERE,
+          base::Bind(&InputEventFilter::ForwardToMainListener,
+                     this, new_msg));
+    }
     return;
   }
 
@@ -199,4 +222,9 @@ void InputEventFilter::SendMessageOnIOThread(const IPC::Message& message) {
   sender_->Send(new IPC::Message(message));
 }
 
+void InputEventFilter::SetHighPriorityTaskRunner(
+    scoped_refptr<base::HighPriorityTaskRunner> high_priority_task_runner) {
+  high_priority_task_runner_ = high_priority_task_runner;
+}
+
 }  // namespace content