Add trace links to chrome://inspect (if chrome://inspect?tracing is used)

chrome/browser/ui/webui/inspect_ui.cc

Index: chrome/browser/ui/webui/inspect_ui.cc
diff --git a/chrome/browser/ui/webui/inspect_ui.cc b/chrome/browser/ui/webui/inspect_ui.cc
index b68586bb027f5daf023de3042424bb93d86d9e10..729942746bdc6f89d5aa06d1c0b91dcf2ea2d559 100644
--- a/chrome/browser/ui/webui/inspect_ui.cc
+++ b/chrome/browser/ui/webui/inspect_ui.cc
@@ -40,6 +40,7 @@ const char kCloseCommand[]  = "close";
 const char kReloadCommand[]  = "reload";
 const char kOpenCommand[]  = "open";
 const char kInspectBrowser[] = "inspect-browser";
+const char kTraceBrowser[] = "trace-browser";
 const char kLocalHost[] = "localhost";
 
 const char kDiscoverUsbDevicesEnabledCommand[] =
@@ -68,6 +69,7 @@ class InspectMessageHandler : public WebUIMessageHandler {
   void HandleReloadCommand(const base::ListValue* args);
   void HandleOpenCommand(const base::ListValue* args);
   void HandleInspectBrowserCommand(const base::ListValue* args);
+  void HandleTraceBrowserCommand(const base::ListValue* args);
   void HandleBooleanPrefChanged(const char* pref_name,
                                 const base::ListValue* args);
   void HandlePortForwardingConfigCommand(const base::ListValue* args);
@@ -110,6 +112,9 @@ void InspectMessageHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback(kInspectBrowser,
       base::Bind(&InspectMessageHandler::HandleInspectBrowserCommand,
                  base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(kTraceBrowser,
+      base::Bind(&InspectMessageHandler::HandleTraceBrowserCommand,
+                 base::Unretained(this)));
 }
 
 void InspectMessageHandler::HandleInitUICommand(const base::ListValue*) {
@@ -173,6 +178,17 @@ void InspectMessageHandler::HandleInspectBrowserCommand(
   }
 }
 
+void InspectMessageHandler::HandleTraceBrowserCommand(
+    const base::ListValue* args) {
+  std::string source_id;
+  std::string browser_id;
+  if (ParseStringArgs(args, &source_id, &browser_id)) {
+    inspect_ui_->InspectBrowserWithCustomFrontend(
+        source_id, browser_id, GURL(std::string(content::kChromeUIScheme)
+          + "://" + content::kChromeUITracingHost));
+  }
+}
+
 void InspectMessageHandler::HandleBooleanPrefChanged(
     const char* pref_name,
     const base::ListValue* args) {