Add metrics for triggering of JS dialogs on Android.

chrome/browser/ui/android/javascript_app_modal_dialog_android.cc

 // Copyright (c) 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 "chrome/browser/ui/android/javascript_app_modal_dialog_android.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
+#include "base/metrics/histogram_macros.h"
+#include "chrome/browser/android/tab_android.h"
 #include "chrome/browser/ui/javascript_dialogs/chrome_javascript_native_dialog_factory.h"
 #include "components/app_modal/app_modal_dialog_queue.h"
 #include "components/app_modal/javascript_app_modal_dialog.h"
 #include "components/app_modal/javascript_dialog_manager.h"
 #include "components/app_modal/javascript_native_dialog_factory.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/common/javascript_message_type.h"
 #include "jni/JavascriptAppModalDialog_jni.h"
@@ skipping 18 matching lines @@
   return 0;
 }
 
 void JavascriptAppModalDialogAndroid::ShowAppModalDialog() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   JNIEnv* env = AttachCurrentThread();
   // Keep a strong ref to the parent window while we make the call to java to
   // display the dialog.
   ScopedJavaLocalRef<jobject> parent_jobj = parent_jobject_weak_ref_.get(env);
-  if (parent_jobj.is_null()) {
+
+  TabAndroid* tab = TabAndroid::FromWebContents(dialog_->web_contents());
+  if (parent_jobj.is_null() || !tab) {
     CancelAppModalDialog();
     return;
   }
 
   ScopedJavaLocalRef<jobject> dialog_object;
   ScopedJavaLocalRef<jstring> title =
       ConvertUTF16ToJavaString(env, dialog_->title());
   ScopedJavaLocalRef<jstring> message =
       ConvertUTF16ToJavaString(env, dialog_->message_text());
 
+  bool foremost = tab->IsUserInteractable();
   switch (dialog_->javascript_message_type()) {
     case content::JAVASCRIPT_MESSAGE_TYPE_ALERT: {
+      UMA_HISTOGRAM_BOOLEAN("JSDialogs.IsForemost.Alert", foremost);
       dialog_object = Java_JavascriptAppModalDialog_createAlertDialog(
           env, title, message, dialog_->display_suppress_checkbox());
       break;
     }
     case content::JAVASCRIPT_MESSAGE_TYPE_CONFIRM: {
       if (dialog_->is_before_unload_dialog()) {
         dialog_object = Java_JavascriptAppModalDialog_createBeforeUnloadDialog(
             env, title, message, dialog_->is_reload(),
             dialog_->display_suppress_checkbox());
       } else {
+        UMA_HISTOGRAM_BOOLEAN("JSDialogs.IsForemost.Confirm", foremost);
         dialog_object = Java_JavascriptAppModalDialog_createConfirmDialog(
             env, title, message, dialog_->display_suppress_checkbox());
       }
       break;
     }
     case content::JAVASCRIPT_MESSAGE_TYPE_PROMPT: {
+      UMA_HISTOGRAM_BOOLEAN("JSDialogs.IsForemost.Prompt", foremost);
       ScopedJavaLocalRef<jstring> default_prompt_text =
           ConvertUTF16ToJavaString(env, dialog_->default_prompt_text());
       dialog_object = Java_JavascriptAppModalDialog_createPromptDialog(
           env, title, message, dialog_->display_suppress_checkbox(),
           default_prompt_text);
       break;
     }
     default:
       NOTREACHED();
   }
@@ skipping 103 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(ChromeJavaScriptNativeDialogAndroidFactory);
 };
 
 }  // namespace
 
 void InstallChromeJavaScriptNativeDialogFactory() {
   app_modal::JavaScriptDialogManager::GetInstance()->SetNativeDialogFactory(
       base::WrapUnique(new ChromeJavaScriptNativeDialogAndroidFactory));
 }