[Autofill] Log the number of autofill profiles available at form submission

components/autofill/core/browser/autofill_manager_unittest.cc

Index: components/autofill/core/browser/autofill_manager_unittest.cc
diff --git a/components/autofill/core/browser/autofill_manager_unittest.cc b/components/autofill/core/browser/autofill_manager_unittest.cc
index 3bfc805d9ecbd20cb2381c709fd177810368cd60..40a67517444036efc0a49a02ac0696d25b3a867c 100644
--- a/components/autofill/core/browser/autofill_manager_unittest.cc
+++ b/components/autofill/core/browser/autofill_manager_unittest.cc
@@ -18,6 +18,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/histogram_tester.h"
 #include "base/time/time.h"
 #include "components/autofill/core/browser/autocomplete_history_manager.h"
 #include "components/autofill/core/browser/autofill_manager.h"
@@ -687,6 +688,7 @@ class AutofillManagerTest : public testing::Test {
 
  protected:
   base::MessageLoop message_loop_;
+  base::HistogramTester histogram_tester_;
   TestAutofillClient autofill_client_;
   scoped_ptr<MockAutofillDriver> autofill_driver_;
   scoped_ptr<TestAutofillManager> autofill_manager_;
@@ -2230,6 +2232,9 @@ TEST_F(AutofillManagerTest, FormSubmitted) {
   // filled data.
   EXPECT_CALL(personal_data_, SaveImportedProfile(::testing::_)).Times(1);
   FormSubmitted(response_data);
+
+  histogram_tester_.ExpectUniqueSample(
+      "Autofill.StoredProfileCountAtAutofillableFormSubmission", 3, 1);

[Ilya Sherman, 2015/01/29 20:34:52]

Please move this test to the autofill_metrics_unittest file, and please write
minimal tests to cover the possible cases.  At the least, I would suggest having
one test for when this histogram is emitted to, and one test verifying that it
is *not* emitted to when a non-autofillable form is submitted.

[Mathieu, 2015/01/30 15:22:41]

Done.

 }
 
 // Test that when Autocomplete is enabled and Autofill is disabled,