Page cyclers: output memory histograms (approach: expose JS object)

This CL makes the chrome browser expose a JS object for retrieving histograms if a command line flag is passed. Page cycler then gets the histograms by executing JS via the test automation API.

BUG=145352


Review URL: https://chromiumcodereview.appspot.com/10905073

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@159668 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 26 insertions, 0 deletions

diff --git a/content/renderer/dom_automation_controller.cc b/content/renderer/dom_automation_controller.cc
index 4c2a717..0ab7035 100644
--- a/content/renderer/dom_automation_controller.cc
+++ b/content/renderer/dom_automation_controller.cc
@@ -7,6 +7,8 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/json/json_string_value_serializer.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/statistics_recorder.h"
 #include "base/string_util.h"
 #include "content/common/view_messages.h"
 
@@ -26,6 +28,9 @@ DomAutomationController::DomAutomationController()
                                       base::Unretained(this)));
   BindCallback("sendWithId", base::Bind(&DomAutomationController::SendWithId,
                                         base::Unretained(this)));
+  BindCallback("getHistogram",
+               base::Bind(&DomAutomationController::GetHistogram,
+                          base::Unretained(this)));
 }
 
 void DomAutomationController::Send(const CppArgumentList& args,
@@ -166,3 +171,20 @@ void DomAutomationController::SetAutomationId(
   automation_id_ = args[0].ToInt32();
   result->Set(true);
 }
+
+void DomAutomationController::GetHistogram(const CppArgumentList& args,
+                                           CppVariant* result) {
+  if (args.size() != 1) {
+    result->SetNull();
+    return;
+  }
+  base::Histogram* histogram =
+      base::StatisticsRecorder::FindHistogram(args[0].ToString());
+  std::string output;
+  if (!histogram) {
+    output = "{}";
+  } else {
+    histogram->WriteJSON(&output);
+  }
+  result->Set(output);
+}
diff --git a/content/renderer/dom_automation_controller.h b/content/renderer/dom_automation_controller.h
index 85bb60b..4550864 100644
--- a/content/renderer/dom_automation_controller.h
+++ b/content/renderer/dom_automation_controller.h
@@ -113,6 +113,10 @@ class DomAutomationController : public webkit_glue::CppBoundClass {
     sender_ = sender;
   }
 
+  // Retrieves a histogram and returns a JSON representation of it.
+  void GetHistogram(const webkit_glue::CppArgumentList& args,
+                    webkit_glue::CppVariant* result);
+
  private:
   IPC::Sender* sender_;