[Content suggestions] Add a feature to fetch favicons from a new server

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 0a268919a1b35d0c32f6acc65993bdfbc6755aad..b792901c849a9029fccf30e3383569eb9fcbc8ee 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -100163,6 +100163,8 @@ from previous Chrome versions.
   <int value="-1399419572" label="enable-app-list"/>
   <int value="-1396974542" label="UserMediaScreenCapturing:enabled"/>
   <int value="-1392562498" label="disable-origin-chip"/>
+  <int value="-1391693054"
+      label="ContentSuggestionsFaviconsFromNewServer:disabled"/>
   <int value="-1386966873" label="disable-mac-views-native-app-windows"/>
   <int value="-1377186702" label="DesktopIOSPromotion:disabled"/>
   <int value="-1375111024" label="enable-fixed-position-compositing"/>
@@ -100350,6 +100352,8 @@ from previous Chrome versions.
   <int value="-610411643" label="enable-printer-app-search"/>
   <int value="-606898702" label="MaterialDesignSettings:disabled"/>
   <int value="-604814313" label="enable-pinch"/>
+  <int value="-604269405"
+      label="ContentSuggestionsFaviconsFromNewServer:enabled"/>
   <int value="-604068396" label="disable-input-ime-api"/>
   <int value="-601384286" label="disable-contextual-search"/>
   <int value="-598050737" label="disable-es3-apis"/>