WIP: Plumbing input event latency reporting through Mus GPU.

ui/events/latency_info.h

Index: ui/events/latency_info.h
diff --git a/ui/events/latency_info.h b/ui/events/latency_info.h
index 8210ae5c1985c294e5e92ed162c0f92ad95dcacf..498e4ccfc96c10ea13358944c0fd0d96c76d009f 100644
--- a/ui/events/latency_info.h
+++ b/ui/events/latency_info.h
@@ -113,6 +113,8 @@ enum SourceEventType {
   SOURCE_EVENT_TYPE_LAST = OTHER,
 };
 
+const char* EVENTS_BASE_EXPORT GetComponentName(ui::LatencyComponentType type);
+
 class EVENTS_BASE_EXPORT LatencyInfo {
  public:
   struct LatencyComponent {
@@ -194,6 +196,13 @@ class EVENTS_BASE_EXPORT LatencyInfo {
                    int64_t id,
                    LatencyComponent* output) const;
 
+  // Returns true if a component with |type| is found in the latency component.
+  // The first such component (when iterating over latency_components_) is
+  // stored to |output| if |output| is not NULL. Returns false if no such
+  // component is found.
+  bool FindLatency(LatencyComponentType type,
+                  LatencyComponent*output) const;
+
   void RemoveLatency(LatencyComponentType type);
 
   // Returns true if there is still room for keeping the |input_coordinate|,