Bug 975931. Part 4: Support reftest-async-scroll attributes. r=dbaron

--HG--
extra : rebase_source : 2f87486f71f6e670df0999e75ac96cc43123921e

layout/tools/reftest/README.txt

@@ -494,6 +494,14 @@ When the "reftest-async-scroll" attribute is set on the root element, *all*
 elements in the document are checked for "reftest-displayport-x/y/w/h" and have
 displayports set on them when those attributes are present.
 
+Testing Async Scrolling: reftest-async-scroll-x/y="<int>"
+=========================================================
+
+When the "reftest-async-scroll" attribute is set on the root element, for any
+element where either the "reftest-async-scroll-x" or "reftest-async-scroll-y
+attributes are nonzero, at the end of the test take the snapshot with the given
+offset (in CSS pixels) added to the async scroll offset.
+
 Printing Tests: class="reftest-print"
 =====================================
 

layout/tools/reftest/reftest-content.js

@@ -183,7 +183,7 @@ function setupPrintMode() {
 }
 
 function attrOrDefault(element, attr, def) {
-    return element.hasAttribute(attr) ? element.getAttribute(attr) : def;
+    return element.hasAttribute(attr) ? Number(element.getAttribute(attr)) : def;
 }
 
 function setupViewport(contentRootElement) {
@@ -221,10 +221,8 @@ function setupDisplayport(contentRootElement) {
 
     function setupDisplayportForElementSubtree(element) {
         setupDisplayportForElement(element);
-        for (var c = element.firstChild; c; c = c.nextSibling) {
-            if (c.nodeType == c.ELEMENT_NODE) {
-                setupDisplayportForElementSubtree(c);
-            }
+        for (var c = element.firstElementChild; c; c = c.nextElementSibling) {
+            setupDisplayportForElementSubtree(c);
         }
     }
 
@@ -236,6 +234,43 @@ function setupDisplayport(contentRootElement) {
     }
 }
 
+function setupAsyncScrollOffsets(options) {
+    var currentDoc = content.document;
+    var contentRootElement = currentDoc ? currentDoc.documentElement : null;
+
+    if (!contentRootElement) {
+        return;
+    }
+
+    function setupAsyncScrollOffsetsForElement(element) {
+        var sx = attrOrDefault(element, "reftest-async-scroll-x", 0);
+        var sy = attrOrDefault(element, "reftest-async-scroll-y", 0);
+        if (sx != 0 || sy != 0) {
+            try {
+                // This might fail when called from RecordResult since layers
+                // may not have been constructed yet
+                windowUtils().setAsyncScrollOffset(element, sx, sy);
+            } catch (e) {
+                if (!options.allowFailure) {
+                    throw e;
+                }
+            }
+        }
+    }
+
+    function setupAsyncScrollOffsetsForElementSubtree(element) {
+        setupAsyncScrollOffsetsForElement(element);
+        for (var c = element.firstElementChild; c; c = c.nextElementSibling) {
+            setupAsyncScrollOffsetsForElementSubtree(c);
+        }
+    }
+
+    var asyncScroll = contentRootElement.hasAttribute("reftest-async-scroll");
+    if (asyncScroll) {
+        setupAsyncScrollOffsetsForElementSubtree(contentRootElement);
+    }
+}
+
 function resetDisplayportAndViewport() {
     // XXX currently the displayport configuration lives on the
     // presshell and so is "reset" on nav when we get a new presshell.
@@ -667,6 +702,9 @@ function RecordResult()
         return;
     }
 
+    // Setup async scroll offsets now in case SynchronizeForSnapshot is not
+    // called (due to reftest-no-sync-layers being supplied).
+    setupAsyncScrollOffsets({allowFailure:true});
     SendTestDone(currentTestRunTime);
     FinishTestItem();
 }
@@ -747,6 +785,10 @@ function SynchronizeForSnapshot(flags)
     var ctx = dummyCanvas.getContext("2d");
     var flags = ctx.DRAWWINDOW_DRAW_CARET | ctx.DRAWWINDOW_DRAW_VIEW | ctx.DRAWWINDOW_USE_WIDGET_LAYERS;
     ctx.drawWindow(content, 0, 0, 1, 1, "rgb(255,255,255)", flags);
+
+    // Setup async scroll offsets now, because any scrollable layers should
+    // have had their AsyncPanZoomControllers created.
+    setupAsyncScrollOffsets({allowFailure:false});
 }
 
 function RegisterMessageListeners()