cros: Log per-process memory use on low memory events

chrome/browser/ui/webui/about_ui.cc

 // Copyright (c) 2012 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/ui/webui/about_ui.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 555 matching lines @@
                                        refresh,
                                        request_id));
 }
 
 std::string AboutDiscardsRun() {
   std::string output;
   AppendHeader(&output, 0, "About discards");
   output.append(StringPrintf("<meta http-equiv=\"refresh\" content=\"2;%s\">",
                              chrome::kChromeUIDiscardsURL));
   output.append(WrapWithTag("p", "Discarding a tab..."));
-  g_browser_process->oom_priority_manager()->DiscardTab();
+  g_browser_process->oom_priority_manager()->LogMemoryAndDiscardTab();
   AppendFooter(&output);
   return output;
 }
 
 std::string AboutDiscards(const std::string& path) {
   std::string output;
   const char kRunCommand[] = "run";
   if (path == kRunCommand)
     return AboutDiscardsRun();
   AppendHeader(&output, 0, "About discards");
@@ skipping 695 matching lines @@
     child_label.append(" (diagnostics)");
   child->SetString("child_name", child_label);
   ListValue* titles = new ListValue();
   child->Set("titles", titles);
   for (size_t i = 0; i < info->titles.size(); ++i)
     titles->Append(new StringValue(info->titles[i]));
 }
 
 
 void AboutMemoryHandler::OnDetailsAvailable() {
+  // TODO(jamescook): Do we want to update UMA stats every time the user opens
+  // an about: page, or only do it periodically?
+  UpdateHistograms();
+
   // the root of the JSON hierarchy for about:memory jstemplate
   DictionaryValue root;
   ListValue* browsers = new ListValue();
   root.Set("browsers", browsers);
 
   const std::vector<ProcessData>& browser_processes = processes();
 
   // Aggregate per-process data into browser summary data.
   std::wstring log_string;
   for (size_t index = 0; index < browser_processes.size(); index++) {
@@ skipping 204 matching lines @@
 }
 
 AboutUI::AboutUI(content::WebUI* web_ui, const std::string& name)
     : WebUIController(web_ui) {
   Profile* profile = Profile::FromWebUI(web_ui);
   ChromeURLDataManager::DataSource* source =
       new AboutUIHTMLSource(name, profile);
   if (source)
     profile->GetChromeURLDataManager()->AddDataSource(source);
 }