Added UMA stat for tracking accidental navigations on double tap.

content/browser/android/content_view_core_impl.cc

 // Copyright 2012 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/browser/android/content_view_core_impl.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/command_line.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "cc/layers/layer.h"
 #include "cc/output/begin_frame_args.h"
 #include "content/browser/android/interstitial_page_delegate_android.h"
 #include "content/browser/android/load_url_params.h"
 #include "content/browser/android/touch_point.h"
 #include "content/browser/media/android/browser_media_player_manager.h"
 #include "content/browser/renderer_host/compositor_impl_android.h"
 #include "content/browser/renderer_host/input/web_input_event_builders_android.h"
@@ skipping 1581 matching lines @@
     // If it was actually enabled globally, enable it for this RenderWidget now.
     if (accessibility_state->IsAccessibleBrowser() && host_impl)
       host_impl->SetAccessibilityMode(AccessibilityModeComplete);
   } else {
     accessibility_state->DisableAccessibility();
     if (host_impl)
       host_impl->SetAccessibilityMode(AccessibilityModeOff);
   }
 }
 
+void ContentViewCoreImpl::SendActionAfterDoubleTapUma(
+    JNIEnv* env,
+    jobject obj,
+    int type,
+    bool hasDelay) {
+  // This UMA stat tracks a user's action after a double tap within
+  // k seconds (where k == 5 currently). This UMA will tell us if
+  // removing the tap gesture delay will lead to significantly more
+  // accidental navigations after a double tap

[Rick Byers, 2013/10/31 17:53:10]

nit - missing .

[bokan, 2013/10/31 22:31:58]

Done.

+  if(hasDelay) {
+      UMA_HISTOGRAM_ENUMERATION("UserInput.ActionAfterDoubleTapWithDelay",
+        type, 3);

[Rick Byers, 2013/10/31 17:53:10]

ugh - hard-coding this 3 is a little unfortunate, but I see the java/native
boundary makes it awkward to do the normal 'MAX' enum thing.  How about just
adding a comment to the enum definition saying to change this line if more
elements are added.

[bokan, 2013/10/31 22:31:58]

It's already there :). But I've gone further and just made the count a param
into this function so updating the enum will be enough.

+  } else {
+      UMA_HISTOGRAM_ENUMERATION("UserInput.ActionAfterDoubleTapNoDelay",
+        type, 3);
+  }
+
+}
+
 void ContentViewCoreImpl::SendOrientationChangeEventInternal() {
   RenderWidgetHostViewAndroid* rwhv = GetRenderWidgetHostViewAndroid();
   if (rwhv)
     rwhv->UpdateScreenInfo(rwhv->GetNativeView());
 
   RenderViewHostImpl* rvhi = static_cast<RenderViewHostImpl*>(
       web_contents_->GetRenderViewHost());
   rvhi->SendOrientationChangeEvent(device_orientation_);
 }
 
 // This is called for each ContentView.
 jint Init(JNIEnv* env, jobject obj,
           jboolean hardware_accelerated,
           jint native_web_contents,
           jint view_android,
           jint window_android) {
   ContentViewCoreImpl* view = new ContentViewCoreImpl(
       env, obj, hardware_accelerated,
       reinterpret_cast<WebContents*>(native_web_contents),
       reinterpret_cast<ui::ViewAndroid*>(view_android),
       reinterpret_cast<ui::WindowAndroid*>(window_android));
   return reinterpret_cast<jint>(view);
 }
 
 bool RegisterContentViewCore(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content