Bug 1582042 - Remove nsIRemoteTab.forceRepaint(). r=mconley

It's useless if the tab is already visible (i.e., has renderLayers=true), per
the previous patches, and that's the only point at which it gets called.

Differential Revision: https://phabricator.services.mozilla.com/D47131

--HG--
extra : moz-landing-system : lando

browser/modules/AsyncTabSwitcher.jsm

@@ -1100,9 +1100,6 @@ class AsyncTabSwitcher {
     this.requestedTab = tab;
     if (tabState == this.STATE_LOADED) {
       this.maybeVisibleTabs.clear();
-      if (tab.linkedBrowser.isRemoteBrowser) {
-        tab.linkedBrowser.forceRepaint();
-      }
     }
 
     tab.linkedBrowser.setAttribute("primary", "true");

dom/interfaces/base/nsIRemoteTab.idl

@@ -33,13 +33,6 @@ interface nsIRemoteTab : nsISupports
    */
   readonly attribute boolean hasLayers;
 
-  /**
-   * Sends a message to the child ensuring that they paint as early as
-   * possible. This will send the message to paint even if renderLayers
-   * is already true.
-   */
-  void forceRepaint();
-
   /**
    * Adjusts the tab's active state in the process priority manager,
    * allowing its process to be given a lower priority.

dom/ipc/BrowserHost.cpp

@@ -195,17 +195,6 @@ BrowserHost::GetHasLayers(bool* aHasLayers) {
   return NS_OK;
 }
 
-/* void forceRepaint (); */
-NS_IMETHODIMP
-BrowserHost::ForceRepaint(void) {
-  if (!mRoot) {
-    return NS_OK;
-  }
-  VisitAll(
-      [](BrowserParent* aBrowserParent) { aBrowserParent->ForceRepaint(); });
-  return NS_OK;
-}
-
 /* void resolutionChanged (); */
 NS_IMETHODIMP
 BrowserHost::NotifyResolutionChanged(void) {

dom/ipc/BrowserParent.cpp

@@ -3315,18 +3315,6 @@ void BrowserParent::PreserveLayers(bool aPreserveLayers) {
   mPreserveLayers = aPreserveLayers;
 }
 
-void BrowserParent::ForceRepaint() {
-  if (!mActiveInPriorityManager) {
-    // If a tab is left and then returned to very rapidly, it can be
-    // deprioritized without losing its loaded status. In this case we won't
-    // go through SetRenderLayers.
-    mActiveInPriorityManager = true;
-    ProcessPriorityManager::TabActivityChanged(this, true);
-  }
-
-  SetRenderLayersInternal(true /* aEnabled */);
-}
-
 void BrowserParent::NotifyResolutionChanged() {
   if (!mIsDestroyed) {
     // TryCacheDPIAndScale()'s cache is keyed off of

dom/ipc/BrowserParent.h

@@ -730,7 +730,6 @@ class BrowserParent final : public PBrowserParent,
   bool GetRenderLayers();
   void SetRenderLayers(bool aRenderLayers);
   void PreserveLayers(bool aPreserveLayers);
-  void ForceRepaint();
   void NotifyResolutionChanged();
 
   void Deprioritize();

toolkit/content/widgets/browser-custom-element.js

@@ -1039,16 +1039,6 @@
       }
     }
 
-    forceRepaint() {
-      if (!this.isRemoteBrowser) {
-        return;
-      }
-      let { frameLoader } = this;
-      if (frameLoader && frameLoader.remoteTab) {
-        frameLoader.remoteTab.forceRepaint();
-      }
-    }
-
     getTabBrowser() {
       if (
         this.ownerGlobal.gBrowser &&