Created the dialog offering the user to merge their account data or keep it

chrome/android/java/strings/android_chrome_strings.grd

Index: chrome/android/java/strings/android_chrome_strings.grd
diff --git a/chrome/android/java/strings/android_chrome_strings.grd b/chrome/android/java/strings/android_chrome_strings.grd
index 7db9c6b6b5293dc682e7a9afc158e9d528841819..b6d4688f65066adf03b147051b1995f8c0cd38f6 100644
--- a/chrome/android/java/strings/android_chrome_strings.grd
+++ b/chrome/android/java/strings/android_chrome_strings.grd
@@ -170,6 +170,9 @@ CHAR-LIMIT guidelines:
       <message name="IDS_NEXT" desc="Generic label for a button to advance to the next item. [CHAR-LIMIT=20]">
         Next
       </message>
+      <message name="IDS_CONT" desc="Generic label for a continue prompt. Used in multiple contexts. [CHAR-LIMIT=20]">
+        Continue
+      </message>
       <message name="IDS_SUBMIT" desc="Generic label for a button to submit data. Used in multiple contexts. [CHAR-LIMIT=20]">
         Submit
       </message>
@@ -1047,11 +1050,26 @@ To obtain new licenses, connect to the internet and play your downloaded content
       <message name="IDS_SYNC_LOADING" desc="Preference title to let the user change their encryption password. [CHAR-LIMIT=20]">
         Loading…
       </message>
+      <message name="IDS_SYNC_IMPORT_DATA_TITLE" desc="Preference title of screen to let user choose to switch sync accounts. [CHAR-LIMIT=24]">
+        Import data?
+      </message>
+      <message name="IDS_SYNC_IMPORT_DATA_PROMPT" desc="Prompt for the user to choose how they want to handle their existing sync data">
+        You are signing in to <ph name="TO_ACCOUNT">%1$s<ex>johndoe@new.com</ex></ph>. Some of your existing bookmarks, history, passwords, and other settings were previously synced to <ph name="FROM_ACCOUNT">%2$s<ex>johndoe@old.com</ex></ph>. What do you want to do with your existing data?
+      </message>
+      <message name="IDS_SYNC_IMPORT_EXISTING_DATA" desc="Option to import existing data to the newly selected sync account">
+        Import existing data
+      </message>
+      <message name="IDS_SYNC_IMPORT_EXISTING_DATA_SUBTEXT" desc="Subtext describing what happens if the user elects to import existing data to the newly selected sync account">
+        Keep existing data on your device and permanently import the data to <ph name="TO_ACCOUNT">%1$s<ex>johndoe@new.com</ex></ph>.
+      </message>
+      <message name="IDS_SYNC_IMPORT_EXISTING_DATA_VALUE" desc="Internal value for import data preference" translateable="false">
+        import_existing_data
+      </message>
       <message name="IDS_SYNC_KEEP_EXISTING_DATA_SEPARATE" desc="Option to keep the existing data separate from the newly selected sync account">
         Keep existing data separate
       </message>
       <message name="IDS_SYNC_KEEP_EXISTING_DATA_SEPARATE_SUBTEXT" desc="Subtext describing what happens if the user elects to keep the existing data separate">
-        Replace this device’s data with <ph name="ACCOUNT">%1$s<ex>john@doe.com</ex></ph>'s data. You can retrieve your existing data by switching back to <ph name="ACCOUNT">%1$s<ex>johndoe@gmail.com</ex></ph>
+        Replace this device’s data with <ph name="TO_ACCOUNT">%1$s<ex>johndoe@new.com</ex></ph>'s data. You can retrieve your existing data by switching back to <ph name="FROM_ACCOUNT">%2$s<ex>johndoe@old.com</ex></ph>, but data created since you signed out will be lost.
       </message>
       <message name="IDS_SYNC_KEEP_EXISTING_DATA_SEPARATE_VALUE" desc="Internal value for keep existing data preference" translateable="false">
         keep_existing_data
@@ -1631,7 +1649,7 @@ You are signing in with a managed account and giving its administrator control o
         Make Chrome yours
       </message>
       <message name="IDS_FRE_NO_ACCOUNT_CHOICE_DESCRIPTION" desc="Text for account chooser page when there are no accounts on the device.">
-        Add an account to get your bookmarks, history, passwords, and other settings on all your devices.
+        Add an account to get your bookmarks, history, passwords, and other settings on all your devices
       </message>
       <message name="IDS_SIGN_IN_TO_CHROME_SUMMARY_VARIANT" desc="A variant of summary for the signin promo; lists reasons to sign in to Chrome.">
         Sign in to access all your web stuff from any device