Add a histogram showing which URL schemes are used by explicitly configured PAC scripts.

Bug: 839566

Change-Id: I51eb05bc52587d84592966870387ccae9d8db5d7
Reviewed-on: https://chromium-review.googlesource.com/1044751
Commit-Queue: Eric Roman <eroman@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Jay Civelli <jcivelli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556992}

net/proxy_resolution/proxy_resolution_service.cc

@@ -15,6 +15,7 @@
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_util.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ -385,6 +386,34 @@ GURL SanitizeUrl(const GURL& url,
   return url.ReplaceComponents(replacements);
 }
 
+// Do not change the enumerated value as it is relied on by histograms.
+enum class PacUrlSchemeForHistogram {
+  kOther = 0,
+
+  kHttp = 1,
+  kHttps = 2,
+  kFtp = 3,
+  kFile = 4,
+  kData = 5,
+
+  kMaxValue = kData,
+};
+
+PacUrlSchemeForHistogram GetPacUrlScheme(const GURL& pac_url) {
+  if (pac_url.SchemeIs("http"))
+    return PacUrlSchemeForHistogram::kHttp;
+  if (pac_url.SchemeIs("https"))
+    return PacUrlSchemeForHistogram::kHttps;
+  if (pac_url.SchemeIs("data"))
+    return PacUrlSchemeForHistogram::kData;
+  if (pac_url.SchemeIs("ftp"))
+    return PacUrlSchemeForHistogram::kFtp;
+  if (pac_url.SchemeIs("file"))
+    return PacUrlSchemeForHistogram::kFile;
+
+  return PacUrlSchemeForHistogram::kOther;
+}
+
 }  // namespace
 
 // ProxyResolutionService::InitProxyResolver ----------------------------------
@@ -1576,6 +1605,11 @@ void ProxyResolutionService::OnProxyConfigChanged(
                                         &fetched_config_, &effective_config));
   }
 
+  if (config.value().has_pac_url()) {
+    UMA_HISTOGRAM_ENUMERATION("Net.ProxyResolutionService.PacUrlScheme",
+                              GetPacUrlScheme(config.value().pac_url()));
+  }
+
   // Set the new configuration as the most recently fetched one.
   fetched_config_ = effective_config;
 

net/proxy_resolution/proxy_resolution_service_unittest.cc

@@ -15,6 +15,7 @@
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/histogram_tester.h"
 #include "net/base/net_errors.h"
 #include "net/base/proxy_delegate.h"
 #include "net/base/proxy_server.h"
@@ -171,6 +172,12 @@ class MockProxyConfigService: public ProxyConfigService {
       observer.OnProxyConfigChanged(config_, availability_);
   }
 
+  void SetPacUrlConfig(base::StringPiece pac_url) {
+    SetConfig(ProxyConfigWithAnnotation(
+        ProxyConfig::CreateFromCustomPacURL(GURL(pac_url)),
+        TRAFFIC_ANNOTATION_FOR_TESTS));
+  }
+
  private:
   ConfigAvailability availability_;
   ProxyConfigWithAnnotation config_;
@@ -333,6 +340,42 @@ JobMap GetCancelledJobsForURLs(const MockAsyncProxyResolver& resolver,
   return GetJobsForURLs(map, urls);
 }
 
+// Helper class to verify the bucket counts for PacUrlScheme histogram.
+class PacUrlSchemeHistogramTester {
+ public:
+  void VerifyHistogram() const {
+    const char kPacUrlSchemeHistogram[] =
+        "Net.ProxyResolutionService.PacUrlScheme";
+
+    int total = GetTotal();
+
+    histograms_.ExpectTotalCount(kPacUrlSchemeHistogram, total);
+
+    if (total > 0) {
+      histograms_.ExpectBucketCount(kPacUrlSchemeHistogram, 0, num_other);
+      histograms_.ExpectBucketCount(kPacUrlSchemeHistogram, 1, num_http);
+      histograms_.ExpectBucketCount(kPacUrlSchemeHistogram, 2, num_https);
+      histograms_.ExpectBucketCount(kPacUrlSchemeHistogram, 3, num_ftp);
+      histograms_.ExpectBucketCount(kPacUrlSchemeHistogram, 4, num_file);
+      histograms_.ExpectBucketCount(kPacUrlSchemeHistogram, 5, num_data);
+    }
+  }
+
+  int num_http = 0;
+  int num_https = 0;
+  int num_ftp = 0;
+  int num_data = 0;
+  int num_file = 0;
+  int num_other = 0;
+
+ private:
+  int GetTotal() const {
+    return num_http + num_https + num_ftp + num_data + num_file + num_other;
+  }
+
+  base::HistogramTester histograms_;
+};
+
 }  // namespace
 
 TEST_F(ProxyResolutionServiceTest, Direct) {
@@ -3576,4 +3619,58 @@ TEST_F(ProxyResolutionServiceTest, OnShutdownFollowedByRequest) {
   EXPECT_TRUE(info.is_direct());
 }
 
+// Tests that the URL scheme for PAC files gets output to the histogram.
+TEST_F(ProxyResolutionServiceTest, PacUrlSchemeHistogram) {
+  PacUrlSchemeHistogramTester pac_histogram;
+
+  MockProxyConfigService* config_service =
+      new MockProxyConfigService(ProxyConfig::CreateDirect());
+
+  ProxyResolutionService service(
+      base::WrapUnique(config_service),
+      std::make_unique<MockAsyncProxyResolverFactory>(false), nullptr);
+
+  pac_histogram.VerifyHistogram();
+
+  // Set an http:// PAC.
+  config_service->SetPacUrlConfig("http://example.test/");
+  pac_histogram.num_http++;
+  pac_histogram.VerifyHistogram();
+
+  // Set an https:// PAC.
+  config_service->SetPacUrlConfig("hTTps://example.test/wpad.dat");
+  pac_histogram.num_https++;
+  pac_histogram.VerifyHistogram();
+
+  // Set an ftp:// PAC.
+  config_service->SetPacUrlConfig("ftp://example.test/pac.js");
+  pac_histogram.num_ftp++;
+  pac_histogram.VerifyHistogram();
+
+  // Set an file:// PAC.
+  config_service->SetPacUrlConfig("file://example.test/boo");
+  pac_histogram.num_file++;
+  pac_histogram.VerifyHistogram();
+
+  // Set an mailto: PAC.
+  config_service->SetPacUrlConfig("mailto:foo@example.test");
+  pac_histogram.num_other++;
+  pac_histogram.VerifyHistogram();
+
+  // Set an data: PAC.
+  config_service->SetPacUrlConfig("data:,Hello%2C%20World!");
+  pac_histogram.num_data++;
+  pac_histogram.VerifyHistogram();
+
+  // Set an filesystem: PAC.
+  config_service->SetPacUrlConfig("filesystem:http://example.test/pac.js");
+  pac_histogram.num_other++;
+  pac_histogram.VerifyHistogram();
+
+  // Set another https:// as PAC.
+  config_service->SetPacUrlConfig("https://example2.test/wpad.dat");
+  pac_histogram.num_https++;
+  pac_histogram.VerifyHistogram();
+}
+
 }  // namespace net

tools/metrics/histograms/enums.xml

@@ -34324,6 +34324,15 @@ Called by update_net_trust_anchors.py.-->
   <int value="7" label="FAIL_DIFFERENT_PROXY_LIST"/>
 </enum>
 
+<enum name="PacUrlScheme">
+  <int value="0" label="Other"/>
+  <int value="1" label="Http"/>
+  <int value="2" label="Https"/>
+  <int value="3" label="Ftp"/>
+  <int value="4" label="File"/>
+  <int value="5" label="Data"/>
+</enum>
+
 <enum name="PageEndReason">
   <int value="0" label="END_NONE">
     Page lifetime has not yet ended (page is still active)

tools/metrics/histograms/histograms.xml

@@ -48413,6 +48413,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Net.ProxyResolutionService.PacUrlScheme" enum="PacUrlScheme">
+  <owner>eroman@chromium.org</owner>
+  <summary>
+    The breakdown of URL schemes seen for explicitly configured ProxyAutoConfig
+    (PAC). This metric is emitted once each time the proxy settings change
+    (including initial value). Note that this does not count implicitly inferred
+    PAC URLs (from WPAD).
+  </summary>
+</histogram>
+
 <histogram name="Net.ProxyResolver.AbandonedExecutionTotalTime" units="ms">
   <obsolete>
     Removed in Chrome 39.