Zoom values for both JS files come from one source

Cleanup during review with @bridiver

browser/resources/extensions/js_override/pdf/viewport.js

@@ -5,7 +5,4 @@
 
 <include src="../../../../../../chrome/browser/resources/pdf/viewport.js">
 
-Viewport.ZOOM_FACTORS = [
-  0.25, 1 / 3, 0.5, 2 / 3, 0.75, 0.8, 0.9, 1, 1.1, 1.25, 1.33, 1.4, 1.5, 1.75, 2, 2.5, 3,
-  4, 5
-];
+Viewport.ZOOM_FACTORS = <include src="../../../settings/zoom_factors.json">;

browser/resources/settings/brave_settings_overrides.js

@@ -105,27 +105,7 @@ const BraveClearSettingsMenuHighlightBehavior = {
 
 const BraveAddZoomLevelsBehavior = {
   ready: function() {
-    this._setPageZoomLevels_([
-        1 / 4,
-        1 / 3,
-        1 / 2,
-        2 / 3,
-        3 / 4,
-        4 / 5,
-        9 / 10,
-        1,
-        11 / 10,
-        5 / 4,
-        4 / 3,
-        7 / 5,
-        3 / 2,
-        7 / 4,
-        2,
-        5 / 2,
-        3,
-        4,
-        5,
-      ])
+    this._setPageZoomLevels_(<include src="./zoom_factors.json">)
   }
 }
 

browser/resources/settings/zoom_factors.json

@@ -0,0 +1,21 @@
+[
+    0.25,
+    1 / 3,
+    0.5,
+    2 / 3,
+    0.75,
+    0.8,
+    0.9,
+    1,
+    1.1,
+    1.25,
+    4 / 3,
+    7 / 5,
+    1.5,
+    1.75,
+    2,
+    2.5,
+    3,
+    4,
+    5
+]

chromium_src/components/zoom/page_zoom_constants.cc

@@ -9,9 +9,8 @@
 
 namespace zoom {
 
-// This list is duplicated in chrome/browser/resources/pdf/viewport.js and in
-// chrome/browser/resources/settings/appearance_page/appearance_page.js. Please
-// make sure the three match.
+// This list is duplicated in brave/browser/resources/settings/zoom_factors.json
+// When changing this list, please make sure that gets updated also.
 const double kPresetZoomFactors[] = {0.25, 1 / 3.0, 0.5, 2 / 3.0, 0.75, 0.8,
                                      0.9, 1.0, 1.1, 1.25, 4 / 3.0, 7 / 5.0,
                                      1.5, 1.75, 2.0, 2.5,