Media Controls: Update PiP button and interstitial strings

Bug: 963032
Change-Id: I347570b37044f9679f94bbe60b9e24d578892ea5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1611216Reviewed-by: Ken Rockot <rockot@google.com>
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660024}

content/app/strings/content_strings.grd

@@ -955,7 +955,7 @@ below:
        Download
       </message>
       <if expr="is_macosx">
-        <message name="IDS_MEDIA_OVERFLOW_MENU_ENTER_PICTURE_IN_PICTURE" desc="Media contr  ls overflow menu item label for a button to enter Picture-in-Picture.">
+        <message name="IDS_MEDIA_OVERFLOW_MENU_ENTER_PICTURE_IN_PICTURE" desc="Media controls overflow menu item label for a button to enter Picture-in-Picture.">
           Picture in Picture
         </message>
       </if>
@@ -966,16 +966,16 @@ below:
       </if>
       <if expr="is_macosx">
         <message name="IDS_MEDIA_OVERFLOW_MENU_EXIT_PICTURE_IN_PICTURE" desc="Media controls overflow menu item label for a button to exit Picture-in-Picture.">
-          Exit Picture in Picture
+          Exit Picture-in-Picture
         </message>
       </if>
       <if expr="not is_macosx">
         <message name="IDS_MEDIA_OVERFLOW_MENU_EXIT_PICTURE_IN_PICTURE" desc="Media controls overflow menu item label for a button to exit Picture-in-Picture.">
-          Exit picture in picture
+          Exit picture-in-picture
         </message>
       </if>
       <message name="IDS_MEDIA_PICTURE_IN_PICTURE_INTERSTITIAL_TEXT" desc="Text message shown to user when in picture in picture mode. When a video is in picture in picture mode, an interstitial with this text appears where the video player is positioned. The video continues to play back in another window that gives the experience that the video is 'popped out'.">
-        Playing in picture-in-picture mode
+        Playing in picture-in-picture
       </message>
       <message name="IDS_MEDIA_REMOTING_CAST_TEXT" desc="Text message shown to the user when casting a video to a known remote device.">
        Now casting to <ph name="DEVICE_FRIENDLY_NAME">$1<ex>Living Room TV</ex></ph>