| Index: composer.postload.js | 
| diff --git a/composer.postload.js b/composer.postload.js | 
| index bab0ea4c63f17d8dda8243403d5c14832107de5f..686da32b61ab1f2802982bbdb26b1d8054bfa317 100644 | 
| --- a/composer.postload.js | 
| +++ b/composer.postload.js | 
| @@ -15,6 +15,8 @@ | 
| * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>. | 
| */ | 
|  | 
| +/* globals checkCollapse, elemhide, getURLsFromElement, typeMap  */ | 
| + | 
| "use strict"; | 
|  | 
| // The page ID for the popup filter selection dialog (top frame only). | 
| @@ -43,8 +45,7 @@ let lastRightClickEventIsMostRecent = false; | 
| function getFiltersForElement(element, callback) | 
| { | 
| let src = element.getAttribute("src"); | 
| -  ext.backgroundPage.sendMessage( | 
| -  { | 
| +  ext.backgroundPage.sendMessage({ | 
| type: "composer.getFilters", | 
| tagName: element.localName, | 
| id: element.id, | 
| @@ -52,7 +53,7 @@ function getFiltersForElement(element, callback) | 
| style: element.getAttribute("style"), | 
| classes: Array.prototype.slice.call(element.classList), | 
| urls: getURLsFromElement(element), | 
| -    mediatype: typeMap[element.localName], | 
| +    mediatype: typeMap.get(element.localName), | 
| baseURL: document.location.href | 
| }, | 
| response => | 
| @@ -72,7 +73,6 @@ function getBlockableElementOrAncestor(element, callback) | 
| // <area> elements (see below). So fall back to the parent element. | 
| if (!(element instanceof HTMLElement) || element.localName == "area") | 
| element = element.parentElement; | 
| - | 
| // If image maps are used mouse events occur for the <area> element. | 
| // But we have to block the image associated with the <map> element. | 
| else if (element.localName == "map") | 
| @@ -388,39 +388,26 @@ function elementPicked(event) | 
| if (currentlyPickingElement) | 
| stopPickingElement(); | 
|  | 
| -    ext.backgroundPage.sendMessage( | 
| -    { | 
| +    ext.backgroundPage.sendMessage({ | 
| type: "composer.openDialog" | 
| }, | 
| popupId => | 
| { | 
| -      ext.backgroundPage.sendMessage( | 
| -      { | 
| +      ext.backgroundPage.sendMessage({ | 
| type: "forward", | 
| targetPageId: popupId, | 
| -        payload: | 
| -        { | 
| -          type: "composer.dialog.init", | 
| -          filters: filters | 
| -        } | 
| +        payload: {type: "composer.dialog.init", filters} | 
| }); | 
|  | 
| // Only the top frame keeps a record of the popup window's ID, | 
| // so if this isn't the top frame we need to pass the ID on. | 
| if (window == window.top) | 
| -      { | 
| blockelementPopupId = popupId; | 
| -      } | 
| else | 
| { | 
| -        ext.backgroundPage.sendMessage( | 
| -        { | 
| +        ext.backgroundPage.sendMessage({ | 
| type: "forward", | 
| -          payload: | 
| -          { | 
| -            type: "composer.content.dialogOpened", | 
| -            popupId: popupId | 
| -          } | 
| +          payload: {type: "composer.content.dialogOpened", popupId} | 
| }); | 
| } | 
| }); | 
| @@ -461,8 +448,7 @@ function deactivateBlockElement() | 
|  | 
| if (blockelementPopupId != null) | 
| { | 
| -    ext.backgroundPage.sendMessage( | 
| -    { | 
| +    ext.backgroundPage.sendMessage({ | 
| type: "forward", | 
| targetPageId: blockelementPopupId, | 
| payload: | 
| @@ -504,8 +490,7 @@ if (document instanceof HTMLDocument) | 
| lastRightClickEvent = event; | 
| lastRightClickEventIsMostRecent = true; | 
|  | 
| -    ext.backgroundPage.sendMessage( | 
| -    { | 
| +    ext.backgroundPage.sendMessage({ | 
| type: "forward", | 
| payload: | 
| { | 
| @@ -520,9 +505,11 @@ if (document instanceof HTMLDocument) | 
| { | 
| case "composer.content.getState": | 
| if (window == window.top) | 
| +        { | 
| sendResponse({ | 
| active: currentlyPickingElement || blockelementPopupId != null | 
| }); | 
| +        } | 
| break; | 
| case "composer.content.startPickingElement": | 
| if (window == window.top) | 
| @@ -572,8 +559,7 @@ if (document instanceof HTMLDocument) | 
| // to be careful here. (This is not perfect, but best we can do.) | 
| if (window == window.top && blockelementPopupId == msg.popupId) | 
| { | 
| -          ext.backgroundPage.sendMessage( | 
| -          { | 
| +          ext.backgroundPage.sendMessage({ | 
| type: "forward", | 
| payload: | 
| { | 
|  |