Connect SparseHistogram with the rest of stats system

chrome/browser/ui/cocoa/browser/password_generation_bubble_controller_unittest.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/browser/password_generation_bubble_controller.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/histogram_samples.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/autofill/password_generator.h"
 #include "chrome/browser/ui/cocoa/cocoa_profile_test.h"
 #include "content/public/common/password_form.h"
 #include "testing/gtest_mac.h"
 
-using base::Histogram;
+using base::HistogramBase;
 using base::HistogramSamples;
 using base::StatisticsRecorder;
 
 const char kHistogramName[] = "PasswordGeneration.UserActions";
 
 class PasswordGenerationBubbleControllerTest : public CocoaProfileTest {
  public:
   PasswordGenerationBubbleControllerTest()
       : controller_(nil) {}
 
   static void SetUpTestCase() {
     StatisticsRecorder::Initialize();
   }
 
   virtual void SetUp() {
     CocoaProfileTest::SetUp();
 
     generator_.reset(new autofill::PasswordGenerator(20));
 
-    Histogram* histogram = StatisticsRecorder::FindHistogram(kHistogramName);
+    HistogramBase* histogram =
+        StatisticsRecorder::FindHistogram(kHistogramName);
     if (histogram)
       original_ = histogram->SnapshotSamples();
 
     SetUpController();
   }
 
   PasswordGenerationBubbleController* controller() { return controller_; }
 
   void SetUpController() {
     content::PasswordForm form;
@@ skipping 10 matching lines @@
                            forForm:form];
   }
 
   void CloseController() {
     [controller_ close];
     [controller_ windowWillClose:nil];
     controller_ = nil;
   }
 
   HistogramSamples* GetHistogramSamples() {
-    Histogram* histogram =
+    HistogramBase* histogram =
         StatisticsRecorder::FindHistogram(kHistogramName);
     if (histogram) {
       current_ = histogram->SnapshotSamples();
       if (original_.get())
         current_->Subtract(*original_.get());
     }
     return current_.get();
   }
 
  protected:
@@ skipping 57 matching lines @@
   [controller() fillPassword:nil];
   CloseController();
 
   samples = GetHistogramSamples();
   EXPECT_EQ(1, samples->GetCount(password_generation::IGNORE_FEATURE));
   EXPECT_EQ(1, samples->GetCount(password_generation::ACCEPT_AFTER_EDITING));
   EXPECT_EQ(1, samples->GetCount(
                 password_generation::ACCEPT_ORIGINAL_PASSWORD));
 
 }