Add logging for slow device events, limit network UI update rate

This CL does the following:
* Cleans up some redundant code in the network UI.
* Disassociates Network UI updates from dbus calls and limits the
  frequency of UI updates by using a timer to trigger updates.
* Adds NET_LOG_IF_SLOW to device_event_log.h to log slow network events.

Note: I also did virtual/override cleanup while in there and ran clang format on the changed files.

BUG=441650

Review URL: https://codereview.chromium.org/811623002

Cr-Commit-Position: refs/heads/master@{#309083}

1 files changed, 20 insertions, 0 deletions

diff --git a/chromeos/device_event_log.cc b/chromeos/device_event_log.cc
index 8251e7d..aaded58 100644
--- a/chromeos/device_event_log.cc
+++ b/chromeos/device_event_log.cc
@@ -17,6 +17,9 @@ namespace {
 
 const size_t kDefaultMaxEntries = 4000;
 
+const int kSlowMethodThresholdMs = 10;
+const int kVerySlowMethodThresholdMs = 50;
+
 DeviceEventLogImpl* g_device_event_log = NULL;
 
 }  // namespace
@@ -83,6 +86,23 @@ DeviceEventLogInstance::~DeviceEventLogInstance() {
   device_event_log::AddEntry(file_, line_, type_, level_, stream_.str());
 }
 
+ScopedDeviceLogIfSlow::ScopedDeviceLogIfSlow(LogType type,
+                                             const char* file,
+                                             const std::string& name)
+    : file_(file), type_(type), name_(name) {
+}
+
+ScopedDeviceLogIfSlow::~ScopedDeviceLogIfSlow() {
+  if (timer_.Elapsed().InMilliseconds() >= kSlowMethodThresholdMs) {
+    LogLevel level(LOG_LEVEL_DEBUG);
+    if (timer_.Elapsed().InMilliseconds() >= kVerySlowMethodThresholdMs)
+      level = LOG_LEVEL_ERROR;
+    DEVICE_LOG(type_, level) << "@@@ Slow method: " << file_ << ":" << name_
+                             << ": " << timer_.Elapsed().InMilliseconds()
+                             << "ms";
+  }
+}
+
 }  // namespace internal
 
 }  // namespace device_event_log