[filesapp] std::string parameters to std::string& in DevToolListener

Change all const std::string into const std::string& to avoid
copying strings on every function invocation.

Test: browser_tests --gtest_filter="*FilesApp*" --devtools-code-coverage
Bug: 1113941
Change-Id: Id3e5a767b575417cf122c85de961e752981ddb16
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2453343
Auto-Submit: Ben Reich <benreich@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814581}

chrome/browser/chromeos/file_manager/devtools_listener.cc

@@ -58,7 +58,7 @@ bool DevToolsListener::HasCoverage(content::DevToolsAgentHost* host) {
 
 void DevToolsListener::GetCoverage(content::DevToolsAgentHost* host,
                                    const base::FilePath& store,
-                                   const std::string test) {
+                                   const std::string& test) {
   if (HasCoverage(host))
     StopAndStoreJSCoverage(host, store, test);
   navigated_ = false;
@@ -72,7 +72,7 @@ void DevToolsListener::Detach(content::DevToolsAgentHost* host) {
 }
 
 std::string DevToolsListener::HostString(content::DevToolsAgentHost* host,
-                                         const std::string prefix = "") {
+                                         const std::string& prefix = "") {
   std::string result = base::StrCat(
       {prefix, " ", host->GetType(), " title: ", host->GetTitle()});
   std::string description = host->GetDescription();
@@ -114,7 +114,7 @@ bool DevToolsListener::StartJSCoverage(content::DevToolsAgentHost* host) {
 
 void DevToolsListener::StopAndStoreJSCoverage(content::DevToolsAgentHost* host,
                                               const base::FilePath& store,
-                                              const std::string test) {
+                                              const std::string& test) {
   std::string precise_coverage =
       "{\"id\":40,\"method\":\"Profiler.takePreciseCoverage\"}";
   host->DispatchProtocolMessage(this, StringToSpan(precise_coverage));

chrome/browser/chromeos/file_manager/devtools_listener.h

@@ -34,7 +34,7 @@ class DevToolsListener : public content::DevToolsAgentHostClient {
   // write it into the |store|.
   void GetCoverage(content::DevToolsAgentHost* host,
                    const base::FilePath& store,
-                   const std::string test);
+                   const std::string& test);
 
   // Detaches from a host.
   void Detach(content::DevToolsAgentHost* host);
@@ -42,7 +42,7 @@ class DevToolsListener : public content::DevToolsAgentHostClient {
   // Returns a string that uniquely identifies a host
   // with an optional prefix.
   static std::string HostString(content::DevToolsAgentHost* host,
-                                const std::string prefix);
+                                const std::string& prefix);
 
  private:
   // Enable CDP on host.
@@ -55,7 +55,7 @@ class DevToolsListener : public content::DevToolsAgentHostClient {
   // it into the |store|.
   void StopAndStoreJSCoverage(content::DevToolsAgentHost* host,
                               const base::FilePath& store,
-                              const std::string test);
+                              const std::string& test);
 
   // Stores scripts that are parsed during execution on host.
   void StoreScripts(content::DevToolsAgentHost* host,