Add PdfHonorJsContentSettings experiment to field trial testing config

Because the field trial testing config is applied to browser_tests,
explicitly disable the "PdfHonorJsContentSettings" feature on tests
that expect the feature disabled.

Bug: 696650
Change-Id: I8b13523b590372230e66c61cf846fca8284112d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2350114
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Auto-Submit: Daniel Hosseinian <dhoss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798827}

chrome/browser/pdf/pdf_extension_test.cc

@@ -932,10 +932,9 @@ class PDFExtensionContentSettingJSTest
  protected:
   void SetUpCommandLine(base::CommandLine* command_line) override {
     PDFExtensionJSTest::SetUpCommandLine(command_line);
-    if (ShouldHonorJsContentSettings()) {
-      feature_list_.InitAndEnableFeature(
-          chrome_pdf::features::kPdfHonorJsContentSettings);
-    }
+    feature_list_.InitWithFeatureState(
+        chrome_pdf::features::kPdfHonorJsContentSettings,
+        ShouldHonorJsContentSettings());
   }
 
   bool ShouldHonorJsContentSettings() const { return GetParam(); }

testing/variations/fieldtrial_testing_config.json

@@ -5347,6 +5347,24 @@
             ]
         }
     ],
+    "PdfHonorJsContentSettings": [
+        {
+            "platforms": [
+                "chromeos",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "PdfHonorJsContentSettings"
+                    ]
+                }
+            ]
+        }
+    ],
     "PerProcessReclaim": [
         {
             "platforms": [