Adding metrics logging for Simplified Gesture Navigation.

content/browser/web_contents/aura/gesture_nav_simple.cc

Index: content/browser/web_contents/aura/gesture_nav_simple.cc
diff --git a/content/browser/web_contents/aura/gesture_nav_simple.cc b/content/browser/web_contents/aura/gesture_nav_simple.cc
index ef727276f381b452bd1050fb611a6bfc64eac8b8..0ed4576a5d0417dc6d72df3db4e8c4453766c6f9 100644
--- a/content/browser/web_contents/aura/gesture_nav_simple.cc
+++ b/content/browser/web_contents/aura/gesture_nav_simple.cc
@@ -7,6 +7,8 @@
 #include <utility>
 
 #include "base/macros.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/metrics/user_metrics.h"
 #include "cc/paint/paint_flags.h"
 #include "components/vector_icons/vector_icons.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
@@ -80,6 +82,17 @@ bool ShouldNavigateBack(const NavigationController& controller,
          controller.CanGoBack();
 }
 
+// Records UMA historgram and also user action for the cancelled overscroll.
+void RecordCancelled(NavigationDirection direction, OverscrollSource source) {
+  UMA_HISTOGRAM_ENUMERATION("Overscroll.Cancelled3",
+                            GetUmaNavigationType(direction, source),
+                            NAVIGATION_TYPE_COUNT);
+  if (direction == NavigationDirection::BACK)
+    RecordAction(base::UserMetricsAction("Overscroll_Cancelled.Back"));
+  else
+    RecordAction(base::UserMetricsAction("Overscroll_Cancelled.Forward"));
+}
+
 }  // namespace
 
 // This class is responsible for creating, painting, and positioning the layer
@@ -391,23 +404,56 @@ void GestureNavSimple::OnOverscrollComplete(OverscrollMode overscroll_mode) {
   CompleteGestureAnimation();
 
   NavigationControllerImpl& controller = web_contents_->GetController();
-  if (ShouldNavigateForward(controller, overscroll_mode))
+  bool navigated = false;
+  if (ShouldNavigateForward(controller, overscroll_mode)) {
     controller.GoForward();
-  else if (ShouldNavigateBack(controller, overscroll_mode))
+    navigated = true;
+  } else if (ShouldNavigateBack(controller, overscroll_mode)) {
     controller.GoBack();
+    navigated = true;
+  }
+
+  if (navigated) {
+    UMA_HISTOGRAM_ENUMERATION("Overscroll.Navigated3",
+                              GetUmaNavigationType(direction_, source_),
+                              UmaNavigationType::NAVIGATION_TYPE_COUNT);
+    if (direction_ == NavigationDirection::BACK)
+      RecordAction(base::UserMetricsAction("Overscroll_Navigated.Back"));
+    else
+      RecordAction(base::UserMetricsAction("Overscroll_Navigated.Forward"));
+  } else {
+    RecordCancelled(direction_, source_);
+  }
+
+  direction_ = NavigationDirection::NONE;
+  source_ = OverscrollSource::NONE;
 }
 
 void GestureNavSimple::OnOverscrollModeChange(OverscrollMode old_mode,
                                               OverscrollMode new_mode,
                                               OverscrollSource source) {
   NavigationControllerImpl& controller = web_contents_->GetController();
-  if (!ShouldNavigateForward(controller, new_mode) &&
-      !ShouldNavigateBack(controller, new_mode)) {
+  if (ShouldNavigateForward(controller, new_mode)) {
+    direction_ = NavigationDirection::FORWARD;
+  } else if (ShouldNavigateBack(controller, new_mode)) {
+    direction_ = NavigationDirection::BACK;
+  } else {
+    // If there is an overscoll in progress - record its cancellation.
+    if (direction_ != NavigationDirection::NONE)
+      RecordCancelled(direction_, source_);
+    direction_ = NavigationDirection::NONE;
+    source_ = OverscrollSource::NONE;
     AbortGestureAnimation();
     return;
   }
 
   DCHECK_NE(source, OverscrollSource::NONE);
+  source_ = source;
+
+  UMA_HISTOGRAM_ENUMERATION("Overscroll.Started3",
+                            GetUmaNavigationType(direction_, source_),
+                            UmaNavigationType::NAVIGATION_TYPE_COUNT);
+
   const float start_threshold = GetOverscrollConfig(
       source == OverscrollSource::TOUCHPAD
           ? OVERSCROLL_CONFIG_HORIZ_THRESHOLD_START_TOUCHPAD