pdf: Add annotation UI entry-point and guard behind feature

[email protected], [email protected]

Bug: 902646
Change-Id: I896f190feeacededc97355d575b8dc3c26b03879
Reviewed-on: https://chromium-review.googlesource.com/c/1329808
Reviewed-by: Henrique Nakashima <[email protected]>
Reviewed-by: Lei Zhang <[email protected]>
Reviewed-by: Ben Wells <[email protected]>
Reviewed-by: dsinclair <[email protected]>
Commit-Queue: dstockwell <[email protected]>
Cr-Commit-Position: refs/heads/master@{#611637}
diff --git a/pdf/pdf_features.cc b/pdf/pdf_features.cc
index 91454c4..2b9d28a7 100644
--- a/pdf/pdf_features.cc
+++ b/pdf/pdf_features.cc
@@ -10,5 +10,8 @@
 const base::Feature kSaveEditedPDFForm{"SaveEditedPDFForm",
                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kPDFAnnotations{"PDFAnnotations",
+                                    base::FEATURE_DISABLED_BY_DEFAULT};
+
 }  // namespace features
 }  // namespace chrome_pdf