Removed requirement for the renderer to know it's process ID

ui/events/latency_info.cc

Index: ui/events/latency_info.cc
diff --git a/ui/events/latency_info.cc b/ui/events/latency_info.cc
index a3a11828db041ee90e844c9076a4d3bd70fb24e3..62a184bf35e5557764089a796fd2594fe21286fb 100644
--- a/ui/events/latency_info.cc
+++ b/ui/events/latency_info.cc
@@ -235,4 +235,40 @@ void LatencyInfo::TraceEventType(const char* event_type) {
                                event_type);
 }
 
+void LatencyInfo::AnnotateWithProcessId(
+    std::vector<ui::LatencyInfo>& latency_info,
+    base::ProcessId process_id) {
+  for (size_t i = 0; i < latency_info.size(); i++) {
+    latency_info[i].AnnotateComponentsWithProcessId(process_id);
+  }
+}
+
+void LatencyInfo::AnnotateComponentsWithProcessId(base::ProcessId process_id) {
+  LatencyMap::iterator lc = latency_components.begin();
+  while (lc != latency_components.end()) {
+    LatencyComponentType component_type = lc->first.first;
+    if (component_type == WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT) {
+      // If the component's process ID is kNullProcessId, patch it with the
+      // correct value.
+      int component_process_id = (lc->first.second >> 32) & 0xffffffff;
+      if (component_process_id == base::kNullProcessId) {
+        // Generate a new component entry
+        int routing_id = lc->first.second & 0xffffffff;
+        int64 id = routing_id | (static_cast<int64>(process_id) << 32);
+        LatencyMap::key_type key = std::make_pair(component_type, id);
+        latency_components[key] = lc->second;
+
+        // Remove the old entry
+        LatencyMap::iterator eraseIter = lc;
+        ++lc;
+        latency_components.erase(eraseIter);
+
+        continue;
+      }
+    }
+
+    ++lc;
+  }
+}
+
 }  // namespace ui