Log the creation of dialog boxes using DialogDelegateView and BubbleDialogDelegateView.

BUG=705331

Review-Url: https://codereview.chromium.org/2867683002
Cr-Commit-Position: refs/heads/master@{#471137}

tools/metrics/histograms/histograms.xml

@@ -11909,6 +11909,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Dialog.Create" enum="BooleanCreated">
+  <owner>pdyson@chromium.org</owner>
+  <summary>
+    Counts the number times dialog boxes are created using a particular parent
+    class.
+  </summary>
+</histogram>
+
 <histogram name="Dialog.Creation" enum="DialogName">
   <owner>pdyson@chromium.org</owner>
   <summary>
@@ -85471,6 +85479,18 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <affected-histogram name="DesktopIOSPromotion.VariationSigninReason"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="DialogTypes" separator="." ordering="prefix">
+  <suffix name="DialogDelegateView"
+      label="Counts dialog boxes created using DialogDelegateView. These are
+             a subset of those created with DialogDelegate."/>
+  <suffix name="BubbleDialogDelegateView"
+      label="Counts dialog boxes created using BubbleDialogDelegateView.
+             These are a subset of those created with DialogDelegateView
+             (which, in turn, are a subset of those created with
+             DialogDelegate)."/>
+  <affected-histogram name="Dialog.Create"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="DiskUsagePerUserCount" separator=".">
   <suffix name="1User" label="Only 1 user exists on device."/>
   <suffix name="2Users" label="2 users exist on device."/>

ui/views/bubble/bubble_dialog_delegate.cc

@@ -4,6 +4,7 @@
 
 #include "ui/views/bubble/bubble_dialog_delegate.h"
 
+#include "base/metrics/histogram_macros.h"
 #include "build/build_config.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/base/default_style.h"
@@ -221,6 +222,7 @@ BubbleDialogDelegateView::BubbleDialogDelegateView(View* anchor_view,
   if (anchor_view)
     SetAnchorView(anchor_view);
   UpdateColorsFromTheme(GetNativeTheme());
+  UMA_HISTOGRAM_BOOLEAN("Dialog.BubbleDialogDelegateView.Create", true);
 }
 
 gfx::Rect BubbleDialogDelegateView::GetBubbleBounds() {

ui/views/window/dialog_delegate.cc

@@ -243,6 +243,7 @@ ui::AXRole DialogDelegate::GetAccessibleWindowRole() const {
 DialogDelegateView::DialogDelegateView() {
   // A WidgetDelegate should be deleted on DeleteDelegate.
   set_owned_by_client();
+  UMA_HISTOGRAM_BOOLEAN("Dialog.DialogDelegateView.Create", true);
 }
 
 DialogDelegateView::~DialogDelegateView() {}