Collect tab timing information for use in telementry-based startup tests

Motivation: Data collection exposed in this CL is needed by upcoming startup tests we're writing using Telemtry.

Expose a new window.statsCollectionController object to JS and move existing histogram reading code into it since that seemed misplaced in DOMAutomationController.

Add a new --enable-stats-collection-bindings to activate said object.

Example usage in telemtry:
with browser.Create() as b:
  b.tabs[0].Navigate("http://www.google.com")
  b.tabs[0].WaitForDocumentReadyStateToBeComplete()
  print b.tabs[0].EvaluateJavaScript('statsCollectionController.tabLoadTiming()')

BUG=None

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=202620

Review URL: https://chromiumcodereview.appspot.com/12389073

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202955 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 334 insertions, 62 deletions

diff --git a/content/browser/histogram_message_filter.cc b/content/browser/histogram_message_filter.cc
index ac08af3..be6f85fc 100644
--- a/content/browser/histogram_message_filter.cc
+++ b/content/browser/histogram_message_filter.cc
@@ -49,17 +49,17 @@ void HistogramMessageFilter::OnGetBrowserHistogram(
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
   // Security: Only allow access to browser histograms when running in the
   // context of a test.
-  bool using_dom_controller =
+  bool using_stats_collection_controller =
       CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kDomAutomationController);
+          switches::kStatsCollectionController);
   bool reduced_security =
       CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kReduceSecurityForDomAutomationTests);
+          switches::kReduceSecurityForStatsCollectionTests);
 
-  if (!using_dom_controller || !reduced_security) {
+  if (!using_stats_collection_controller || !reduced_security) {
     LOG(ERROR) << "Attempt at reading browser histogram without specifying "
-               << "--" << switches::kDomAutomationController << " and "
-               << "--" << switches::kReduceSecurityForDomAutomationTests
+               << "--" << switches::kStatsCollectionController << " and "
+               << "--" << switches::kReduceSecurityForStatsCollectionTests
                << " switches.";
     return;
   }
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 499f161..e341a4a 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -941,6 +941,7 @@ void RenderProcessHostImpl::PropagateBrowserCommandLineToRenderer(
     switches::kRendererStartupDialog,
     switches::kShowPaintRects,
     switches::kSitePerProcess,
+    switches::kStatsCollectionController,
     switches::kTestSandbox,
     switches::kTouchEvents,
     switches::kTraceStartup,
diff --git a/content/content_renderer.gypi b/content/content_renderer.gypi
index b064a01..6ea4c3f 100644
--- a/content/content_renderer.gypi
+++ b/content/content_renderer.gypi
@@ -313,6 +313,10 @@
     'renderer/skia_benchmarking_extension.h',
     'renderer/speech_recognition_dispatcher.cc',
     'renderer/speech_recognition_dispatcher.h',
+    'renderer/stats_collection_controller.cc',
+    'renderer/stats_collection_controller.h',
+    'renderer/stats_collection_observer.cc',
+    'renderer/stats_collection_observer.h',
     'renderer/text_input_client_observer.cc',
     'renderer/text_input_client_observer.h',
     'renderer/v8_value_converter_impl.cc',
diff --git a/content/public/common/bindings_policy.h b/content/public/common/bindings_policy.h
index 140cef3..8c8a743 100644
--- a/content/public/common/bindings_policy.h
+++ b/content/public/common/bindings_policy.h
@@ -20,6 +20,11 @@ enum BindingsPolicy {
   BINDINGS_POLICY_DOM_AUTOMATION = 1 << 1,
   // Bindings that allow access to the external host (through automation).
   BINDINGS_POLICY_EXTERNAL_HOST = 1 << 2,
+  // Bindings that allows the JS content to retrieve a variety of internal
+  // metrics. (By default this isn't allowed unless the app has been started up
+  // with the --enable-stats-collection-bindings switch.)
+  BINDINGS_POLICY_STATS_COLLECTION = 1 << 3,
+
 };
 
 }
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 664b87f..d153e2e 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -247,8 +247,15 @@ const char kDomAutomationController[]       = "dom-automation";
 
 // Loosen security. Needed for tests using some of the functionality of
 // |DOMAutomationController|.
-const char kReduceSecurityForDomAutomationTests[] =
-    "reduce-security-for-dom-automation-tests";
+const char kReduceSecurityForStatsCollectionTests[] =
+    "reduce-security-for-stats-collection-tests";
+
+// Specifies if the |StatsCollectionController| needs to be bound in the
+// renderer. This binding happens on per-frame basis and hence can potentially
+// be a performance bottleneck. One should only enable it when running a test
+// that needs to access the provided statistics.
+const char kStatsCollectionController[] =
+    "enable-stats-collection-bindings";
 
 // Enable gpu-accelerated SVG/W3C filters.
 const char kEnableAcceleratedFilters[]      = "enable-accelerated-filters";
diff --git a/content/public/common/content_switches.h b/content/public/common/content_switches.h
index 2356f0c..8e76c71 100644
--- a/content/public/common/content_switches.h
+++ b/content/public/common/content_switches.h
@@ -92,7 +92,8 @@ extern const char kDisableWebSecurity[];
 extern const char kEnableExperimentalWebSocket[];
 extern const char kDisableXSSAuditor[];
 CONTENT_EXPORT extern const char kDomAutomationController[];
-CONTENT_EXPORT extern const char kReduceSecurityForDomAutomationTests[];
+CONTENT_EXPORT extern const char kReduceSecurityForStatsCollectionTests[];
+CONTENT_EXPORT extern const char kStatsCollectionController[];
 CONTENT_EXPORT extern const char kEnableAcceleratedFilters[];
 extern const char kEnableAccessibilityLogging[];
 extern const char kEnableAudibleNotifications[];
diff --git a/content/renderer/dom_automation_controller.cc b/content/renderer/dom_automation_controller.cc
index 1718d64..27120c1 100644
--- a/content/renderer/dom_automation_controller.cc
+++ b/content/renderer/dom_automation_controller.cc
@@ -31,12 +31,6 @@ DomAutomationController::DomAutomationController()
                                       base::Unretained(this)));
   BindCallback("sendWithId", base::Bind(&DomAutomationController::SendWithId,
                                         base::Unretained(this)));
-  BindCallback("getHistogram",
-               base::Bind(&DomAutomationController::GetHistogram,
-                          base::Unretained(this)));
-  BindCallback("getBrowserHistogram",
-               base::Bind(&DomAutomationController::GetBrowserHistogram,
-                          base::Unretained(this)));
 }
 
 void DomAutomationController::Send(const CppArgumentList& args,
@@ -177,40 +171,4 @@ void DomAutomationController::SetAutomationId(
   result->Set(true);
 }
 
-void DomAutomationController::GetHistogram(const CppArgumentList& args,
-                                           CppVariant* result) {
-  if (args.size() != 1) {
-    result->SetNull();
-    return;
-  }
-  base::HistogramBase* histogram =
-      base::StatisticsRecorder::FindHistogram(args[0].ToString());
-  std::string output;
-  if (!histogram) {
-    output = "{}";
-  } else {
-    histogram->WriteJSON(&output);
-  }
-  result->Set(output);
-}
-
-void DomAutomationController::GetBrowserHistogram(const CppArgumentList& args,
-                                                  CppVariant* result) {
-  if (args.size() != 1) {
-    result->SetNull();
-    return;
-  }
-
-  if (!sender_) {
-    NOTREACHED();
-    result->SetNull();
-    return;
-  }
-
-  std::string histogram_json;
-  sender_->Send(new ChildProcessHostMsg_GetBrowserHistogram(
-      args[0].ToString(), &histogram_json));
-  result->Set(histogram_json);
-}
-
 }  // namespace content
diff --git a/content/renderer/dom_automation_controller.h b/content/renderer/dom_automation_controller.h
index b4fe4c0..1516eea 100644
--- a/content/renderer/dom_automation_controller.h
+++ b/content/renderer/dom_automation_controller.h
@@ -115,15 +115,6 @@ 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);
-
-  // Retrieves a histogram from the browser process and returns a JSON
-  // representation of it.
-  void GetBrowserHistogram(const webkit_glue::CppArgumentList& args,
-                           webkit_glue::CppVariant* result);
-
  private:
   IPC::Sender* sender_;
 
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 3efa0f5..7bce363 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -111,6 +111,8 @@
 #include "content/renderer/renderer_webcolorchooser_impl.h"
 #include "content/renderer/savable_resources.h"
 #include "content/renderer/speech_recognition_dispatcher.h"
+#include "content/renderer/stats_collection_controller.h"
+#include "content/renderer/stats_collection_observer.h"
 #include "content/renderer/text_input_client_observer.h"
 #include "content/renderer/v8_value_converter_impl.h"
 #include "content/renderer/web_ui_extension.h"
@@ -713,6 +715,9 @@ void RenderViewImpl::Initialize(RenderViewImplParams* params) {
 
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
+  if (command_line.HasSwitch(switches::kStatsCollectionController))
+    stats_collection_observer_.reset(new StatsCollectionObserver(this));
+
 #if defined(OS_ANDROID)
   content::DeviceTelephonyInfo device_info;
 
@@ -802,6 +807,8 @@ void RenderViewImpl::Initialize(RenderViewImplParams* params) {
 
   if (command_line.HasSwitch(switches::kDomAutomationController))
     enabled_bindings_ |= BINDINGS_POLICY_DOM_AUTOMATION;
+  if (command_line.HasSwitch(switches::kStatsCollectionController))
+    enabled_bindings_ |= BINDINGS_POLICY_STATS_COLLECTION;
 
   ProcessViewLayoutFlags(command_line);
 
@@ -3654,6 +3661,15 @@ void RenderViewImpl::didClearWindowObject(WebFrame* frame) {
     dom_automation_controller_->BindToJavascript(frame,
                                                  "domAutomationController");
   }
+
+   if (enabled_bindings_ & BINDINGS_POLICY_STATS_COLLECTION) {
+     if (!stats_collection_controller_.get())
+       stats_collection_controller_.reset(new StatsCollectionController());
+     stats_collection_controller_->set_message_sender(
+         static_cast<RenderView*>(this));
+     stats_collection_controller_->BindToJavascript(frame,
+                                                  "statsCollectionController");
+   }
 }
 
 void RenderViewImpl::didCreateDocumentElement(WebFrame* frame) {
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index 28fec34..292cb30 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -38,6 +38,7 @@
 #include "content/renderer/render_view_pepper_helper.h"
 #include "content/renderer/render_widget.h"
 #include "content/renderer/renderer_webcookiejar_impl.h"
+#include "content/renderer/stats_collection_observer.h"
 #include "ipc/ipc_platform_file.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebFileSystem.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
@@ -164,6 +165,7 @@ class RendererPpapiHost;
 class RendererWebColorChooserImpl;
 class RenderWidgetFullscreenPepper;
 class SpeechRecognitionDispatcher;
+class StatsCollectionController;
 class WebPluginDelegateProxy;
 struct CustomContextMenuContext;
 struct FaviconURL;
@@ -267,6 +269,12 @@ class CONTENT_EXPORT RenderViewImpl
   void AddObserver(RenderViewObserver* observer);
   void RemoveObserver(RenderViewObserver* observer);
 
+  // Returns the StatsCollectionObserver associated with this view, or NULL
+  // if one wasn't created;
+  StatsCollectionObserver* GetStatsCollectionObserver() {
+    return stats_collection_observer_.get();
+  }
+
   // Adds the given file chooser request to the file_chooser_completion_ queue
   // (see that var for more) and requests the chooser be displayed if there are
   // no other waiting items in the queue.
@@ -1518,14 +1526,20 @@ class CONTENT_EXPORT RenderViewImpl
   // DOM automation bindings are enabled.
   scoped_ptr<DomAutomationController> dom_automation_controller_;
 
+   // Allows JS to read out a variety of internal various metrics. The JS object
+   // is only exposed when the stats collection bindings are enabled.
+   scoped_ptr<StatsCollectionController> stats_collection_controller_;
+
   // This field stores drag/drop related info for the event that is currently
   // being handled. If the current event results in starting a drag/drop
   // session, this info is sent to the browser along with other drag/drop info.
   DragEventSourceInfo possible_drag_event_info_;
 
-  // NOTE: pepper_helper_ should be last member because its constructor calls
-  // AddObservers method of RenderViewImpl from c-tor.
+  // NOTE: pepper_helper_ and stats_collection_observer_ should be the last
+  // members because their constructors call the AddObservers method of
+  // RenderViewImpl.
   scoped_ptr<RenderViewPepperHelper> pepper_helper_;
+  scoped_ptr<StatsCollectionObserver> stats_collection_observer_;
 
   // ---------------------------------------------------------------------------
   // ADDING NEW DATA? Please see if it fits appropriately in one of the above
diff --git a/content/renderer/stats_collection_controller.cc b/content/renderer/stats_collection_controller.cc
new file mode 100644
index 0000000..9826eef
--- /dev/null
+++ b/content/renderer/stats_collection_controller.cc
@@ -0,0 +1,159 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/renderer/stats_collection_controller.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/json/json_writer.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/statistics_recorder.h"
+#include "base/string_util.h"
+#include "content/common/child_process_messages.h"
+#include "content/renderer/render_view_impl.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
+
+using webkit_glue::CppArgumentList;
+using webkit_glue::CppVariant;
+
+namespace content {
+
+namespace {
+
+bool CurrentRenderViewImpl(RenderViewImpl** out) {
+  WebKit::WebFrame* web_frame = WebKit::WebFrame::frameForCurrentContext();
+  if (!web_frame)
+    return false;
+
+  WebKit::WebView* web_view = web_frame->view();
+  if (!web_view)
+    return false;
+
+  RenderViewImpl* render_view_impl =
+      RenderViewImpl::FromWebView(web_view);
+  if (!render_view_impl)
+    return false;
+
+  *out = render_view_impl;
+  return true;
+}
+
+// Encodes a WebContentsLoadTime as JSON.
+// Input:
+// - |load_start_time| - time at which page load started.
+// - |load_stop_time| - time at which page load stopped.
+// - |result| - returned JSON.
+// Example return value:
+// {'load_start_ms': 1, 'load_duration_ms': 2.5}
+// either value may be null if a web contents hasn't fully loaded.
+// load_start_ms is represented as milliseconds since system boot.
+void ConvertLoadTimeToJSON(
+    const base::TimeTicks& load_start_time,
+    const base::TimeTicks& load_stop_time,
+    std::string *result) {
+  DictionaryValue item;
+
+  if (load_start_time.is_null()) {
+     item.Set("load_start_ms", Value::CreateNullValue());
+  } else {
+    // This code relies on an implementation detail of TimeTicks::Now() - that
+    // its return value happens to coincide with the system uptime value in
+    // microseconds, on Win/Mac/iOS/Linux/ChromeOS and Android.  See comments
+    // in base::SysInfo::Uptime().
+    item.SetDouble("load_start_ms", load_start_time.ToInternalValue() / 1000);
+  }
+  if (load_stop_time.is_null() || load_stop_time.is_null()) {
+    item.Set("load_duration_ms", Value::CreateNullValue());
+  } else {
+    item.SetDouble("load_duration_ms",
+        (load_stop_time - load_start_time).InMilliseconds());
+  }
+  base::JSONWriter::Write(&item, result);
+}
+
+}  // namespace
+
+StatsCollectionController::StatsCollectionController()
+    : sender_(NULL) {
+  BindCallback("getHistogram",
+               base::Bind(&StatsCollectionController::GetHistogram,
+                          base::Unretained(this)));
+  BindCallback("getBrowserHistogram",
+               base::Bind(&StatsCollectionController::GetBrowserHistogram,
+                          base::Unretained(this)));
+  BindCallback("tabLoadTiming",
+               base::Bind(
+                  &StatsCollectionController::GetTabLoadTiming,
+                  base::Unretained(this)));
+}
+
+void StatsCollectionController::GetHistogram(const CppArgumentList& args,
+                                            CppVariant* result) {
+  if (args.size() != 1) {
+    result->SetNull();
+    return;
+  }
+  base::HistogramBase* histogram =
+      base::StatisticsRecorder::FindHistogram(args[0].ToString());
+  std::string output;
+  if (!histogram) {
+    output = "{}";
+  } else {
+    histogram->WriteJSON(&output);
+  }
+  result->Set(output);
+}
+
+void StatsCollectionController::GetBrowserHistogram(const CppArgumentList& args,
+                                                   CppVariant* result) {
+  if (args.size() != 1) {
+    result->SetNull();
+    return;
+  }
+
+  if (!sender_) {
+    NOTREACHED();
+    result->SetNull();
+    return;
+  }
+
+  std::string histogram_json;
+  sender_->Send(new ChildProcessHostMsg_GetBrowserHistogram(
+      args[0].ToString(), &histogram_json));
+  result->Set(histogram_json);
+}
+
+void StatsCollectionController::GetTabLoadTiming(
+    const CppArgumentList& args,
+    CppVariant* result) {
+  if (!sender_) {
+    NOTREACHED();
+    result->SetNull();
+    return;
+  }
+
+  RenderViewImpl *render_view_impl = NULL;
+  if (!CurrentRenderViewImpl(&render_view_impl)) {
+    NOTREACHED();
+    result->SetNull();
+    return;
+  }
+
+  StatsCollectionObserver* observer =
+      render_view_impl->GetStatsCollectionObserver();
+  if (!observer) {
+    NOTREACHED();
+    result->SetNull();
+    return;
+  }
+
+  std::string tab_timing_json;
+  ConvertLoadTimeToJSON(
+      observer->load_start_time(), observer->load_stop_time(),
+      &tab_timing_json);
+  result->Set(tab_timing_json);
+}
+
+}  // namespace content
diff --git a/content/renderer/stats_collection_controller.h b/content/renderer/stats_collection_controller.h
new file mode 100644
index 0000000..eb1ccb0
--- /dev/null
+++ b/content/renderer/stats_collection_controller.h
@@ -0,0 +1,43 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_RENDERER_STATS_COLLECTION_CONTROLLER_H_
+#define CONTENT_RENDERER_STATS_COLLECTION_CONTROLLER_H_
+
+#include "ipc/ipc_sender.h"
+#include "webkit/glue/cpp_bound_class.h"
+
+namespace content {
+
+// This class is exposed in JS as window.statsCollectionController and provides
+// functionality to read out statistics from the browser.
+// Its use must be enabled specifically via the
+// --enable-stats-collection-bindings command line flag.
+class StatsCollectionController : public webkit_glue::CppBoundClass {
+ public:
+  StatsCollectionController();
+
+  void set_message_sender(IPC::Sender* sender) {
+    sender_ = sender;
+  }
+
+  // Retrieves a histogram and returns a JSON representation of it.
+  void GetHistogram(const webkit_glue::CppArgumentList& args,
+                    webkit_glue::CppVariant* result);
+
+  // Retrieves a histogram from the browser process and returns a JSON
+  // representation of it.
+  void GetBrowserHistogram(const webkit_glue::CppArgumentList& args,
+                           webkit_glue::CppVariant* result);
+
+  // Returns JSON representation of tab timing information for the current tab.
+  void GetTabLoadTiming(const webkit_glue::CppArgumentList& args,
+                        webkit_glue::CppVariant* result);
+ private:
+  IPC::Sender* sender_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_STATS_COLLECTION_CONTROLLER_H_
diff --git a/content/renderer/stats_collection_observer.cc b/content/renderer/stats_collection_observer.cc
new file mode 100644
index 0000000..4192ec0
--- /dev/null
+++ b/content/renderer/stats_collection_observer.cc
@@ -0,0 +1,33 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/renderer/stats_collection_observer.h"
+
+#include "base/time.h"
+#include "content/renderer/render_view_impl.h"
+
+namespace content {
+
+StatsCollectionObserver::StatsCollectionObserver(RenderViewImpl* render_view)
+    : RenderViewObserver(render_view) {
+}
+
+StatsCollectionObserver::~StatsCollectionObserver() {
+}
+
+void StatsCollectionObserver::DidStartLoading() {
+  DCHECK(start_time_.is_null());
+  start_time_ = base::TimeTicks::Now();
+}
+
+void StatsCollectionObserver::DidStopLoading() {
+  DCHECK(stop_time_.is_null());
+  stop_time_ = base::TimeTicks::Now();
+
+  // Stop observing so we don't get called again.
+  RenderViewImpl* impl = static_cast<RenderViewImpl*>(render_view());
+  impl->RemoveObserver(this);
+}
+
+}  // namespace content
diff --git a/content/renderer/stats_collection_observer.h b/content/renderer/stats_collection_observer.h
new file mode 100644
index 0000000..52d67b8
--- /dev/null
+++ b/content/renderer/stats_collection_observer.h
@@ -0,0 +1,40 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_RENDERER_STATS_COLLECTION_OBSERVER_H_
+#define CONTENT_RENDERER_STATS_COLLECTION_OBSERVER_H_
+
+#include "base/time.h"
+#include "content/public/renderer/render_view_observer.h"
+
+namespace content {
+
+class RenderViewImpl;
+
+// Collect timing information for page loads.
+// If a Renderview performs multiple loads, only the first one is recorded.
+class StatsCollectionObserver : public RenderViewObserver {
+ public:
+  explicit StatsCollectionObserver(RenderViewImpl* render_view);
+  virtual ~StatsCollectionObserver();
+
+  // RenderViewObserver implementation
+  virtual void DidStartLoading() OVERRIDE;
+  virtual void DidStopLoading() OVERRIDE;
+
+  // Timing for the page load start and stop.  These functions may return
+  // a null time value under various circumstances.
+  const base::TimeTicks& load_start_time() { return start_time_; }
+  const base::TimeTicks& load_stop_time() { return stop_time_; }
+
+ private:
+  base::TimeTicks start_time_;
+  base::TimeTicks stop_time_;
+
+   DISALLOW_COPY_AND_ASSIGN(StatsCollectionObserver);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_STATS_COLLECTION_OBSERVER_H_