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::RecordEnumeratedHistogram(const std::string& name,
+                                                   int sample,
+                                                   int boundary_value) {
+  if (!(boundary_value >= 0 && boundary_value < 100 && sample >= 0 &&
+        sample < boundary_value)) {
+    frontend_host_->BadMessageRecieved();
+    return;
+  }
+  // Each histogram name must follow a different code path in
+  // order to UMA_HISTOGRAM_ENUMERATION work correctly.
+  if (name == kDevToolsActionTakenHistogram)
+    UMA_HISTOGRAM_ENUMERATION(name, sample, boundary_value);
+  else if (name == kDevToolsPanelShownHistogram)
+    UMA_HISTOGRAM_ENUMERATION(name, sample, boundary_value);
+  else
+    frontend_host_->BadMessageRecieved();
+}
+
 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();
 }