Added UMA stat for tracking accidental navigations on double tap.

content/browser/android/content_view_core_impl.cc

Index: content/browser/android/content_view_core_impl.cc
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index c423adb26a525acca2f5cb89f0401acbcca22de2..860f069260f99ce7ff3482a8e00f9b7e893c2612 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -11,6 +11,7 @@
 #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"
@@ -1620,6 +1621,31 @@ void ContentViewCoreImpl::SetAccessibilityEnabled(JNIEnv* env, jobject obj,
   }
 }
 
+void ContentViewCoreImpl::SendSingleTapUma(JNIEnv* env,
+                                           jobject obj,

[Ted C, 2013/11/07 04:26:08]

I can't say I'm a big fan of this living within ContentViewCore.  I'd rather the
gesture handler track this themselves.  Unfortunately, there are no native
components nor any upstream UMA dumping grounds exposed in java, so I guess this
is the best we've got.

+                                           jint type,
+                                           jint count) {
+  UMA_HISTOGRAM_ENUMERATION("Event.SingleTapType", type, count);
+}
+
+void ContentViewCoreImpl::SendActionAfterDoubleTapUma(JNIEnv* env,
+                                                      jobject obj,
+                                                      jint type,
+                                                      jboolean has_delay,
+                                                      jint count) {
+  // 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.
+  if (has_delay) {
+      UMA_HISTOGRAM_ENUMERATION("Event.ActionAfterDoubleTapWithDelay", type,

[Ted C, 2013/11/07 04:26:08]

-2 indent

[bokan, 2013/11/07 06:26:42]

Done.

+                                count);
+  } else {
+      UMA_HISTOGRAM_ENUMERATION("Event.ActionAfterDoubleTapNoDelay", type,

[Ted C, 2013/11/07 04:26:08]

same

[bokan, 2013/11/07 06:26:42]

Done.

+                                count);
+  }
+}
+
 void ContentViewCoreImpl::SendOrientationChangeEventInternal() {
   RenderWidgetHostViewAndroid* rwhv = GetRenderWidgetHostViewAndroid();
   if (rwhv)