Report frequency of single page app navigations to UMA

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index 23b058dc70155aed38401d5d15f0860ebd8d6adb..a99a75e90d185f7aaa0a7df98d4877b91cb92ec1 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -79,6 +79,7 @@
 #include "core/probe/CoreProbes.h"
 #include "core/svg/graphics/SVGImage.h"
 #include "core/xml/parser/XMLDocumentParser.h"
+#include "platform/Histogram.h"
 #include "platform/InstanceCounters.h"
 #include "platform/PluginScriptForbiddenScope.h"
 #include "platform/ScriptForbiddenScope.h"
@@ -484,6 +485,35 @@ void FrameLoader::UpdateForSameDocumentNavigation(
     HistoryScrollRestorationType scroll_restoration_type,
     FrameLoadType type,
     Document* initiating_document) {
+  // This enum is used to index different kinds of single-page-application
+  // navigations for UMA enum histogram. New enum values can be added, but
+  // existing enums must never be renumbered or deleted and reused.
+  // This enum should be consistent with SinglePageAppNavigationType in
+  // tools/metrics/histograms/enums.
+  enum SinglePageAppNavigationType {
+    kSPANavTypeHistoryPushStateOrReplaceState = 0,
+    kSPANavTypeSameDocumentBackwardOrForward = 1,
+    kSPANavTypeOtherFragmentNavigation = 2,
+    kSPANavTypeCount = kSPANavTypeOtherFragmentNavigation + 1,
+  };
+  const char* histogramName =
+      "RendererScheduler.UpdateForSameDocumentNavigationCount";
+  if (same_document_navigation_source == kSameDocumentNavigationHistoryApi) {

[Liquan (Max) Gu, 2017/06/16 17:37:35]

Can I assume that these three conditions are exclusive and there is no such
situation where (source == kSameDocumentNavigationHistoryApi && type ==
kFrameLoadTypeBackForward)

+    UMA_HISTOGRAM_ENUMERATION(histogramName,
+                              kSPANavTypeHistoryPushStateOrReplaceState,
+                              kSPANavTypeCount);
+  }
+  if (type == kFrameLoadTypeBackForward) {
+    UMA_HISTOGRAM_ENUMERATION(histogramName,
+                              kSPANavTypeSameDocumentBackwardOrForward,
+                              kSPANavTypeCount);
+  }
+  if (same_document_navigation_source == kSameDocumentNavigationDefault &&
+      type != kFrameLoadTypeBackForward) {
+    UMA_HISTOGRAM_ENUMERATION(histogramName, kSPANavTypeOtherFragmentNavigation,
+                              kSPANavTypeCount);
+  }
+
   TRACE_EVENT1("blink", "FrameLoader::updateForSameDocumentNavigation", "url",
                new_url.GetString().Ascii().data());