Bug 1912570. Record/warn in reftests/crashtests if compositor is paused or window is fully occluded. r=jwatt

Differential Revision: https://phabricator.services.mozilla.com/D219005

dom/base/nsDOMWindowUtils.cpp

@@ -1708,6 +1708,27 @@ nsDOMWindowUtils::GetIsMozAfterPaintPending(bool* aResult) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsDOMWindowUtils::GetIsWindowFullyOccluded(bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = false;
+  if (nsIWidget* widget = GetWidget()) {
+    *aResult = widget->IsFullyOccluded();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDOMWindowUtils::GetIsCompositorPaused(bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = false;
+  CompositorBridgeChild* cbc = GetCompositorBridge();
+  if (cbc) {
+    *aResult = cbc->IsPaused();
+  }
+  return NS_OK;
+}
+
 NS_IMETHODIMP
 nsDOMWindowUtils::GetIsInputTaskManagerSuspended(bool* aResult) {
   *aResult = InputTaskManager::Get()->IsSuspended();

dom/interfaces/base/nsIDOMWindowUtils.idl

@@ -1014,6 +1014,10 @@ interface nsIDOMWindowUtils : nsISupports {
    */
   readonly attribute boolean isMozAfterPaintPending;
 
+  readonly attribute boolean isWindowFullyOccluded;
+
+  readonly attribute boolean isCompositorPaused;
+
   /**
    * Returns true if the InputTaskManager is suspended.
    */

layout/tools/reftest/reftest.sys.mjs

@@ -886,6 +886,16 @@ async function StartCurrentURI(aURLTargetType) {
     }
   }
 
+  if (g.windowUtils.isWindowFullyOccluded || g.windowUtils.isCompositorPaused) {
+    logger.warning(
+      "g.windowUtils.isWindowFullyOccluded " +
+        g.windowUtils.isWindowFullyOccluded
+    );
+    logger.warning(
+      "g.windowUtils.isCompositorPaused " + g.windowUtils.isCompositorPaused
+    );
+  }
+
   if (
     !prefSettings.length &&
     g.uriCanvases[g.currentURL] &&
@@ -912,6 +922,20 @@ async function StartCurrentURI(aURLTargetType) {
         "%)\n"
     );
     TestBuffer("START " + g.currentURL);
+
+    if (
+      g.windowUtils.isWindowFullyOccluded ||
+      g.windowUtils.isCompositorPaused
+    ) {
+      TestBuffer(
+        "g.windowUtils.isWindowFullyOccluded " +
+          g.windowUtils.isWindowFullyOccluded
+      );
+      TestBuffer(
+        "g.windowUtils.isCompositorPaused " + g.windowUtils.isCompositorPaused
+      );
+    }
+
     await updateBrowserRemotenessByURL(g.browser, g.currentURL);
 
     if (prefsRequireRefresh) {
@@ -1121,6 +1145,16 @@ async function UpdateWholeCurrentCanvasForInvalidation() {
 function RecordResult(testRunTime, errorMsg, typeSpecificResults) {
   TestBuffer("RecordResult fired");
 
+  if (g.windowUtils.isWindowFullyOccluded || g.windowUtils.isCompositorPaused) {
+    TestBuffer(
+      "g.windowUtils.isWindowFullyOccluded " +
+        g.windowUtils.isWindowFullyOccluded
+    );
+    TestBuffer(
+      "g.windowUtils.isCompositorPaused " + g.windowUtils.isCompositorPaused
+    );
+  }
+
   // Keep track of which test was slowest, and how long it took.
   if (testRunTime > g.slowestTestTime) {
     g.slowestTestTime = testRunTime;

widget/nsBaseWidget.h

@@ -706,6 +706,7 @@ class nsBaseWidget : public nsIWidget, public nsSupportsWeakReference {
   bool mUseAttachedEvents;
   bool mIMEHasFocus;
   bool mIMEHasQuit;
+  // if the window is fully occluded (rendering may be paused in response)
   bool mIsFullyOccluded;
   bool mNeedFastSnaphot;
   // This flag is only used when APZ is off. It indicates that the current pan