Turn extension script injection histograms into uma histograms....

chrome/renderer/user_script_slave.cc

Index: chrome/renderer/user_script_slave.cc
===================================================================
--- chrome/renderer/user_script_slave.cc	(revision 27493)
+++ chrome/renderer/user_script_slave.cc	(working copy)
@@ -123,7 +123,8 @@
     return true;
 
   PerfTimer timer;
-  int num_matched = 0;
+  int num_css = 0;
+  int num_scripts = 0;
 
   for (size_t i = 0; i < scripts_.size(); ++i) {
     std::vector<WebScriptSource> sources;
@@ -131,9 +132,9 @@
     if (!script->MatchesUrl(frame->url()))
       continue;  // This frame doesn't match the script url pattern, skip it.
 
-    ++num_matched;
     // CSS files are always injected on document start before js scripts.
     if (location == UserScript::DOCUMENT_START) {
+      num_css += script->css_scripts().size();
       for (size_t j = 0; j < script->css_scripts().size(); ++j) {
         UserScript::File& file = script->css_scripts()[j];
         frame->insertStyleText(
@@ -141,6 +142,7 @@
       }
     }
     if (script->run_location() == location) {
+      num_scripts += script->js_scripts().size();
       for (size_t j = 0; j < script->js_scripts().size(); ++j) {
         UserScript::File &file = script->js_scripts()[j];
         std::string content = file.GetContent().as_string();
@@ -174,14 +176,15 @@
 
   // Log debug info.
   if (location == UserScript::DOCUMENT_START) {
-    HISTOGRAM_COUNTS_100("UserScripts:DocStart:Count", num_matched);
-    HISTOGRAM_TIMES("UserScripts:DocStart:Time", timer.Elapsed());
+    UMA_HISTOGRAM_COUNTS_100("Extensions.InjectStart_CssCount", num_css);
+    UMA_HISTOGRAM_COUNTS_100("Extensions.InjectStart_ScriptCount", num_scripts);
+    UMA_HISTOGRAM_TIMES("Extensions.InjectStart_Time", timer.Elapsed());
   } else {
-    HISTOGRAM_COUNTS_100("UserScripts:DocEnd:Count", num_matched);
-    HISTOGRAM_TIMES("UserScripts:DocEnd:Time", timer.Elapsed());
+    UMA_HISTOGRAM_COUNTS_100("Extensions.InjectEnd_ScriptCount", num_scripts);
+    UMA_HISTOGRAM_TIMES("Extensions.InjectEnd_Time", timer.Elapsed());

[jar (doing other things), 2009/09/29 20:55:02]

Note: This histogram has a maximum value of 10 seconds.  Unless you consistently
expect these times to be much smaller (sub-1-second?), you may want a histogram
with wider range.  Keep in mind that this will run on much slower computers in
the field.

See histogram.h for the clear spec of what each of these macros will do.

[asargent_no_longer_on_chrome, 2009/09/30 23:36:46]

Thanks for the heads up. We expect these values to generally be less than
50-100ms, and anything over 1s to indicate a serious problem, so 10 seconds as
the max value should be fine.

   }
 
-  LOG(INFO) << "Injected " << num_matched << " user scripts into " <<
-      frame->url().spec().data();
+  LOG(INFO) << "Injected " << num_scripts << " scripts and " << num_css <<
+      "css files into " << frame->url().spec().data();
   return true;
 }