Devtools: UMA for InspectElement loading time was added

BUG=

Review URL: https://codereview.chromium.org/137383005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247994 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/devtools/devtools_embedder_message_dispatcher.cc

@@ -161,6 +161,9 @@ DevToolsEmbedderMessageDispatcher::DevToolsEmbedderMessageDispatcher(
   RegisterHandler("setContentsInsets",
       BindToListParser(base::Bind(&Delegate::SetContentsInsets,
                                   base::Unretained(delegate))));
+  RegisterHandler("inspectElementCompleted",
+        BindToListParser(base::Bind(&Delegate::InspectElementCompleted,
+                                    base::Unretained(delegate))));
   RegisterHandler("moveWindowBy",
       BindToListParser(base::Bind(&Delegate::MoveWindow,
                                   base::Unretained(delegate))));

chrome/browser/devtools/devtools_embedder_message_dispatcher.h

@@ -30,6 +30,7 @@ class DevToolsEmbedderMessageDispatcher {
     virtual void CloseWindow() = 0;
     virtual void SetContentsInsets(
         int top, int left, int bottom, int right) = 0;
+    virtual void InspectElementCompleted() = 0;
     virtual void MoveWindow(int x, int y) = 0;
     virtual void SetIsDocked(bool is_docked) = 0;
     virtual void OpenInNewTab(const std::string& url) = 0;

chrome/browser/devtools/devtools_window.cc

@@ -10,10 +10,12 @@
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
+#include "base/metrics/histogram.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ -469,9 +471,13 @@ void DevToolsWindow::InspectElement(content::RenderViewHost* inspected_rvh,
   scoped_refptr<DevToolsAgentHost> agent(
       DevToolsAgentHost::GetOrCreateFor(inspected_rvh));
   agent->InspectElement(x, y);
+  bool should_measure_time = FindDevToolsWindow(agent.get()) == NULL;
+  base::TimeTicks start_time = base::TimeTicks::Now();
   // TODO(loislo): we should initiate DevTools window opening from within
   // renderer. Otherwise, we still can hit a race condition here.
-  OpenDevToolsWindow(inspected_rvh);
+  DevToolsWindow* window = OpenDevToolsWindow(inspected_rvh);
+  if (should_measure_time)
+    window->inspect_element_start_time_ = start_time;
 }
 
 // static
@@ -1013,6 +1019,14 @@ void DevToolsWindow::SetContentsInsets(
   }
 }
 
+void DevToolsWindow::InspectElementCompleted() {
+  if (!inspect_element_start_time_.is_null()) {
+    UMA_HISTOGRAM_TIMES("DevTools.InspectElement",
+        base::TimeTicks::Now() - inspect_element_start_time_);
+    inspect_element_start_time_ = base::TimeTicks();
+  }
+}
+
 void DevToolsWindow::MoveWindow(int x, int y) {
   if (!is_docked_) {
     gfx::Rect bounds = browser_->window()->GetBounds();

chrome/browser/devtools/devtools_window.h

@@ -301,6 +301,7 @@ class DevToolsWindow : private content::NotificationObserver,
   virtual void CloseWindow() OVERRIDE;
   virtual void SetContentsInsets(
       int left, int top, int right, int bottom) OVERRIDE;
+  virtual void InspectElementCompleted() OVERRIDE;
   virtual void MoveWindow(int x, int y) OVERRIDE;
   virtual void SetIsDocked(bool is_docked) OVERRIDE;
   virtual void OpenInNewTab(const std::string& url) OVERRIDE;
@@ -388,6 +389,7 @@ class DevToolsWindow : private content::NotificationObserver,
 
   scoped_ptr<DevToolsEmbedderMessageDispatcher> embedder_message_dispatcher_;
   base::WeakPtrFactory<DevToolsWindow> weak_factory_;
+  base::TimeTicks inspect_element_start_time_;
   DISALLOW_COPY_AND_ASSIGN(DevToolsWindow);
 };
 

tools/metrics/histograms/histograms.xml

@@ -1834,6 +1834,13 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="DevTools.InspectElement" units="milliseconds">
+  <summary>
+    Time to load Developer Tools when user clicks Inspect Element in the context
+    menu.
+  </summary>
+</histogram>
+
 <histogram name="Diagnostics.Recovery.ConflictingDlls" enum="DiagnosticsResult">
   <summary>
     TBD - Not run automatically yet, so this is just a placeholder for future