Replace deprecated use of GetVariationParamValue with GetFieldTrialParamValueByFeature

Since we're wrapping up one experiment for CSD on Desktop (vision-based
CSD) and moving immediately into another (the new DOM-based model),
take this opportunity to remove the legacy usage of
GetVariationParamValue on Desktop.

Change-Id: Idc153248827e48fdd53d6b062fc32285644d3204
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2551458Reviewed-by: Bettina Dea <bdea@chromium.org>
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829828}

chrome/browser/safe_browsing/client_side_model_loader.cc

@@ -23,6 +23,7 @@
 #include "base/time/time.h"
 #include "components/safe_browsing/buildflags.h"
 #include "components/safe_browsing/core/db/v4_protocol_manager_util.h"
+#include "components/safe_browsing/core/features.h"
 #include "components/safe_browsing/core/proto/client_model.pb.h"
 #include "components/safe_browsing/core/proto/csd.pb.h"
 #include "components/variations/variations_associated_data.h"
@@ -63,10 +64,8 @@ const char ModelLoader::kClientModelUrlPrefix[] =
     "https://ssl.gstatic.com/safebrowsing/csd/";
 const char ModelLoader::kClientModelNamePattern[] =
     "client_model_v5%s_variation_%d.pb";
+#if !BUILDFLAG(FULL_SAFE_BROWSING)
 const char ModelLoader::kClientModelFinchExperiment[] =
-#if BUILDFLAG(FULL_SAFE_BROWSING)
-    "ClientSideDetectionModel";
-#else
     "ClientSideDetectionModelOnAndroid";
 #endif
 const char ModelLoader::kClientModelFinchParam[] =
@@ -80,8 +79,13 @@ const char kOverrideCsdModelFlag[] = "csd-model-override-path";
 
 // static
 int ModelLoader::GetModelNumber() {
+#if BUILDFLAG(FULL_SAFE_BROWSING)
+  std::string num_str = base::GetFieldTrialParamValueByFeature(
+      kClientSideDetectionModelVersion, kClientModelFinchParam);
+#else
   std::string num_str = variations::GetVariationParamValue(
       kClientModelFinchExperiment, kClientModelFinchParam);
+#endif
   int model_number = 0;
   if (!base::StringToInt(num_str, &model_number)) {
     model_number = 6;  // Default model

chrome/browser/safe_browsing/client_side_model_loader_unittest.cc

@@ -20,6 +20,8 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/time/time.h"
+#include "components/safe_browsing/buildflags.h"
+#include "components/safe_browsing/core/features.h"
 #include "components/safe_browsing/core/proto/client_model.pb.h"
 #include "components/safe_browsing/core/proto/csd.pb.h"
 #include "components/variations/variations_associated_data.h"
@@ -76,6 +78,13 @@ class ModelLoaderTest : public testing::Test {
   // Set up the finch experiment to control the model number
   // used in the model URL. This clears all existing state.
   void SetFinchModelNumber(int model_number) {
+#if BUILDFLAG(FULL_SAFE_BROWSING)
+    scoped_feature_list_.Reset();
+    scoped_feature_list_.InitAndEnableFeatureWithParameters(
+        kClientSideDetectionModelVersion,
+        {{ ModelLoader::kClientModelFinchParam,
+           base::NumberToString(model_number) }});
+#else
     scoped_feature_list_.Reset();
     scoped_feature_list_.Init();
     variations::testing::ClearAllVariationIDs();
@@ -91,6 +100,7 @@ class ModelLoaderTest : public testing::Test {
 
     ASSERT_TRUE(variations::AssociateVariationParams(
         ModelLoader::kClientModelFinchExperiment, group_name, params));
+#endif
   }
 
   // Set the URL for future SetModelFetchResponse() calls.

components/safe_browsing/core/features.cc

@@ -36,6 +36,9 @@ const base::Feature kCaptureInlineJavascriptForGoogleAds{
 const base::Feature kClientSideDetectionForAndroid{
     "ClientSideDetectionModelOnAndroid", base::FEATURE_DISABLED_BY_DEFAULT};
 
+extern const base::Feature kClientSideDetectionModelVersion{
+    "ClientSideDetectionModel", base::FEATURE_ENABLED_BY_DEFAULT};
+
 const base::Feature kDelayedWarnings{"SafeBrowsingDelayedWarnings",
                                      base::FEATURE_DISABLED_BY_DEFAULT};
 

components/safe_browsing/core/features.h

@@ -37,6 +37,10 @@ extern const base::Feature kCaptureInlineJavascriptForGoogleAds;
 // Enables client side detection on Android.
 extern const base::Feature kClientSideDetectionForAndroid;
 
+// Determines the experimental version of client side detection model, for
+// Desktop.
+extern const base::Feature kClientSideDetectionModelVersion;
+
 // Enable the addition of access tokens to download pings for enhanced
 // protection users.
 extern const base::Feature kDownloadRequestWithToken;