[Password Generation] Update UMA stats for popups per page not per event.

chrome/renderer/autofill/password_generation_agent_browsertest.cc

 // Copyright 2013 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 <string.h>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/histogram_tester.h"
 #include "chrome/test/base/chrome_render_view_test.h"
 #include "components/autofill/content/common/autofill_messages.h"
 #include "components/autofill/content/renderer/autofill_agent.h"
 #include "components/autofill/content/renderer/test_password_generation_agent.h"
 #include "components/autofill/core/common/form_data.h"
+#include "components/autofill/core/common/password_generation_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebWidget.h"
 
 using blink::WebDocument;
 using blink::WebElement;
 using blink::WebInputElement;
 using blink::WebNode;
@@ skipping 225 matching lines @@
 
   // Receive the account creation forms detected message. Show password
   // generation icon.
   LoadHTML(kAccountCreationFormHTML);
   SetNotBlacklistedMessage(kAccountCreationFormHTML);
   SetAccountCreationFormsDetectedMessage(kAccountCreationFormHTML);
   ExpectPasswordGenerationAvailable("first_password", true);
 }
 
 TEST_F(PasswordGenerationAgentTest, MaximumOfferSize) {
+  base::HistogramTester histogram_tester;
+
   LoadHTML(kAccountCreationFormHTML);
   SetNotBlacklistedMessage(kAccountCreationFormHTML);
   SetAccountCreationFormsDetectedMessage(kAccountCreationFormHTML);
   ExpectPasswordGenerationAvailable("first_password", true);
 
   WebDocument document = GetMainFrame()->document();
   WebElement element =
       document.getElementById(WebString::fromUTF8("first_password"));
   ASSERT_FALSE(element.isNull());
   WebInputElement first_password_element = element.to<WebInputElement>();
@@ skipping 52 matching lines @@
   ExecuteJavaScript("document.getElementById('username').focus();");
   EXPECT_EQ(0u, password_generation_->messages().size());
   password_generation_->clear_messages();
 
   // Focusing the password field will bring up the generation UI again.
   ExecuteJavaScript("document.getElementById('first_password').focus();");
   EXPECT_EQ(1u, password_generation_->messages().size());
   EXPECT_EQ(AutofillHostMsg_ShowPasswordGenerationPopup::ID,
             password_generation_->messages()[0]->type());
   password_generation_->clear_messages();
+
+  // Loading a different page triggers UMA stat upload. Verify that only one
+  // display event is sent even though
+  LoadHTML(kSigninFormHTML);
+
+  histogram_tester.ExpectBucketCount(
+      "PasswordGeneration.Event",
+      autofill::password_generation::GENERATION_POPUP_SHOWN,
+      1);
 }
 
 }  // namespace autofill