DevTools: introduce RecordEnumeratedHistogram method.

chrome/browser/devtools/devtools_ui_bindings.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/devtools/devtools_ui_bindings.h"
 
 #include "base/command_line.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/metrics/histogram.h"
@@ skipping 731 matching lines @@
     agent_host_->DispatchProtocolMessage(message);
 }
 
 void DevToolsUIBindings::RecordActionUMA(const std::string& name, int action) {
   if (name == kDevToolsActionTakenHistogram)
     UMA_HISTOGRAM_ENUMERATION(name, action, kDevToolsActionTakenBoundary);
   else if (name == kDevToolsPanelShownHistogram)
     UMA_HISTOGRAM_ENUMERATION(name, action, kDevToolsPanelShownBoundary);
 }
 
+void DevToolsUIBindings::RecordUMA(const std::string& name,
+                                   int action,
+                                   int bucket_size) {
+  CHECK(0 < bucket_size && bucket_size < 100);

[Tom Sepez, 2015/04/03 17:46:51]

CHECK-ing in the browser is bad when the renderer is at fault.  If any of the
conditions here aren't met (including an unknown name below), you want to
terminate the renderer (e.g. BadMessageReceived() if it's available in this
context). 

[lushnikov, 2015/04/06 10:10:39]

Done.

+  CHECK(0 <= action && action < bucket_size);
+
+  if (name == kDevToolsActionTakenHistogram ||
+      name == kDevToolsPanelShownHistogram)
+    UMA_HISTOGRAM_ENUMERATION(name, action, bucket_size);
+}
+
 void DevToolsUIBindings::SendJsonRequest(const DispatchCallback& callback,
                                          const std::string& browser_id,
                                          const std::string& url) {
   if (!android_bridge_) {
     callback.Run(nullptr);
     return;
   }
   android_bridge_->SendJsonRequest(browser_id, url,
       base::Bind(&DevToolsUIBindings::JsonReceived,
                  weak_factory_.GetWeakPtr(),
@@ skipping 248 matching lines @@
   if (frontend_loaded_)
     return;
   frontend_loaded_ = true;
 
   // Call delegate first - it seeds importants bit of information.
   delegate_->OnLoadCompleted();
 
   UpdateTheme();
   AddDevToolsExtensionsToClient();
 }