Revert "[ozone/wayland] Introduced the histogram to track time on data transfer."

This reverts commit d1224786.

Reason for revert: Suspect this CL breaks the build android-archive-rel. First failure: https://ci.chromium.org/p/chromium/builders/ci/android-archive-rel/16867
Compile error message: expand_owners.Error: The histogram Event.WaylandDragDrop.IncomingDataTransferTime must have a valid primary owner, i.e. a Googler with an @google.com or @chromium.org email address.

Original change's description:
> [ozone/wayland] Introduced the histogram to track time on data transfer.
>
> When data is dragged from another application into Chromium, there is a
> delay between mouse pointer crossing the window border and the actual
> OnDragEnter() called on the window.  The delay happens because the
> drag drop controller has to get the data, which implies at least one
> request to the Wayland server (the actual number of requests equals
> number of MIME types available in the data offer).
>
> Here a histogram is introduced to know what the real delays will be
> there in the wild.
>
> Bug: 1147413
> Change-Id: I2f3acc067f718ccb29d98ea1bf98b9f03efc2f7d
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2552864
> Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
> Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
> Commit-Queue: Alexander Dunaev <adunaev@igalia.com>
> Cr-Commit-Position: refs/heads/master@{#831251}

TBR=rjkroege@chromium.org,asvitkine@chromium.org,adunaev@igalia.com

Change-Id: I8a9f113d12f7c8ef7e71989cdb3949696a683901
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1147413
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2561958Reviewed-by: Maggie Cai <mxcai@chromium.org>
Commit-Queue: Maggie Cai <mxcai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#831254}

tools/metrics/histograms/histograms_xml/event/histograms.xml

@@ -1640,16 +1640,6 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
-<histogram name="Event.WaylandDragDrop.IncomingDataTransferTime" units="ms"
-    expires_after="M90">
-  <owner>adunaev@igalia.com</owner>
-  <owner>rjkroege@chromium.org</owner>
-  <summary>
-    Delay between the drag coming into the window and the window is actually
-    notified.
-  </summary>
-</histogram>
-
 <histogram base="true" name="EventLatency" units="microseconds"
     expires_after="2021-05-09">
   <owner>mohsen@chromium.org</owner>

ui/ozone/platform/wayland/host/wayland_data_drag_controller.cc

@@ -7,7 +7,6 @@
 #include <cstdint>
 
 #include "base/check.h"
-#include "base/metrics/histogram_macros.h"
 #include "base/notreached.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/base/clipboard/clipboard_constants.h"
@@ -161,7 +160,7 @@ void WaylandDataDragController::OnDragEnter(WaylandWindow* window,
     received_data_ = std::make_unique<OSExchangeData>(
         std::make_unique<OSExchangeDataProviderNonBacked>());
     last_drag_location_ = location;
-    HandleUnprocessedMimeTypes(base::TimeTicks::Now());
+    HandleUnprocessedMimeTypes();
   }
 }
 
@@ -282,23 +281,21 @@ void WaylandDataDragController::CreateIconSurfaceIfNeeded(
 // more unprocessed mime types on the |unprocessed_mime_types_| queue. Once this
 // process is finished, OnDataTransferFinished is called to deliver the
 // |received_data_| to the drop handler.
-void WaylandDataDragController::HandleUnprocessedMimeTypes(
-    base::TimeTicks start_time) {
+void WaylandDataDragController::HandleUnprocessedMimeTypes() {
   DCHECK_EQ(state_, State::kTransferring);
   std::string mime_type = GetNextUnprocessedMimeType();
   if (mime_type.empty() || is_leave_pending_) {
-    OnDataTransferFinished(start_time, std::move(received_data_));
+    OnDataTransferFinished(std::move(received_data_));
   } else {
     DCHECK(data_offer_);
     data_device_->RequestData(
         data_offer_.get(), mime_type,
         base::BindOnce(&WaylandDataDragController::OnMimeTypeDataTransferred,
-                       weak_factory_.GetWeakPtr(), start_time));
+                       weak_factory_.GetWeakPtr()));
   }
 }
 
 void WaylandDataDragController::OnMimeTypeDataTransferred(
-    base::TimeTicks start_time,
     PlatformClipboard::Data contents) {
   DCHECK_EQ(state_, State::kTransferring);
   DCHECK(contents);
@@ -309,11 +306,10 @@ void WaylandDataDragController::OnMimeTypeDataTransferred(
   unprocessed_mime_types_.pop_front();
 
   // Continue reading data for other negotiated mime types.
-  HandleUnprocessedMimeTypes(start_time);
+  HandleUnprocessedMimeTypes();
 }
 
 void WaylandDataDragController::OnDataTransferFinished(
-    base::TimeTicks start_time,
     std::unique_ptr<OSExchangeData> received_data) {
   unprocessed_mime_types_.clear();
   state_ = State::kIdle;
@@ -333,9 +329,6 @@ void WaylandDataDragController::OnDataTransferFinished(
     return;
   }
 
-  UMA_HISTOGRAM_TIMES("Event.WaylandDragDrop.IncomingDataTransferTime",
-                      base::TimeTicks::Now() - start_time);
-
   PropagateOnDragEnter(last_drag_location_, std::move(received_data));
 }
 

ui/ozone/platform/wayland/host/wayland_data_drag_controller.h

@@ -105,11 +105,9 @@ class WaylandDataDragController : public WaylandDataDevice::DragDelegate,
 
   void Offer(const OSExchangeData& data, int operation);
   void CreateIconSurfaceIfNeeded(const OSExchangeData& data);
-  void HandleUnprocessedMimeTypes(base::TimeTicks start_time);
-  void OnMimeTypeDataTransferred(base::TimeTicks start_time,
-                                 PlatformClipboard::Data contents);
+  void HandleUnprocessedMimeTypes();
+  void OnMimeTypeDataTransferred(PlatformClipboard::Data contents);
   void OnDataTransferFinished(
-      base::TimeTicks start_time,
       std::unique_ptr<ui::OSExchangeData> received_data);
   std::string GetNextUnprocessedMimeType();
   // Calls the window's OnDragEnter with the given location and data,