Bug 1137944 - On Windows defer composition until we receive confirmation plugin window metrics have been updated. r=roc

gfx/layers/ipc/CompositorChild.cpp

@@ -318,6 +318,9 @@ CompositorChild::RecvUpdatePluginConfigurations(const nsIntPoint& aContentOffset
   // Any plugins we didn't update need to be hidden, as they are
   // not associated with visible content.
   nsIWidget::UpdateRegisteredPluginWindowVisibility((uintptr_t)parent, visiblePluginIds);
+#if defined(XP_WIN)
+  SendRemotePluginsReady();
+#endif
   return true;
 #endif // !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
 }
@@ -333,6 +336,9 @@ CompositorChild::RecvHideAllPlugins(const uintptr_t& aParentWidget)
   MOZ_ASSERT(NS_IsMainThread());
   nsTArray<uintptr_t> list;
   nsIWidget::UpdateRegisteredPluginWindowVisibility(aParentWidget, list);
+#if defined(XP_WIN)
+  SendRemotePluginsReady();
+#endif
   return true;
 #endif // !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
 }

gfx/layers/ipc/CompositorParent.cpp

@@ -56,6 +56,7 @@
 #include "nsTArray.h"                   // for nsTArray
 #include "nsThreadUtils.h"              // for NS_IsMainThread
 #include "nsXULAppAPI.h"                // for XRE_GetIOMessageLoop
+#include "nsIXULRuntime.h"              // for BrowserTabsRemoteAutostart
 #ifdef XP_WIN
 #include "mozilla/layers/CompositorD3D11.h"
 #include "mozilla/layers/CompositorD3D9.h"
@@ -554,6 +555,9 @@ CompositorParent::CompositorParent(nsIWidget* aWidget,
 #if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
   , mLastPluginUpdateLayerTreeId(0)
 #endif
+#if defined(XP_WIN)
+  , mPluginUpdateResponsePending(false)
+#endif
 {
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(CompositorThread(),
@@ -1043,13 +1047,57 @@ CompositorParent::CompositeToTarget(DrawTarget* aTarget, const gfx::IntRect* aRe
     return;
   }
 
-  AutoResolveRefLayers resolve(mCompositionManager, true);
+#if defined(XP_WIN)
+  // Still waiting on plugin update confirmation
+  if (mPluginUpdateResponsePending) {
+    return;
+  }
+#endif
+
+  bool hasRemoteContent = false;
+  bool pluginsUpdatedFlag = true;
+  AutoResolveRefLayers resolve(mCompositionManager, this,
+                               &hasRemoteContent,
+                               &pluginsUpdatedFlag);
 
 #if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+  /*
+   * AutoResolveRefLayers handles two tasks related to Windows and Linux
+   * plugin window management:
+   * 1) calculating if we have remote content in the view. If we do not have
+   * remote content, all plugin windows for this CompositorParent (window)
+   * can be hidden since we do not support plugins in chrome when running
+   * under e10s.
+   * 2) Updating plugin position, size, and clip. We do this here while the
+   * remote layer tree is hooked up to to chrome layer tree. This is needed
+   * since plugin clipping can depend on chrome (for example, due to tab modal
+   * prompts). Updates in step 2 are applied via an async ipc message sent
+   * to the main thread.
+   * Windows specific: The compositor will wait for confirmation that plugin
+   * updates have been applied before painting. Deferment of painting is
+   * indicated by the mPluginUpdateResponsePending flag. The main thread
+   * messages back using the RemotePluginsReady async ipc message.
+   * This is neccessary since plugin windows can leave remnants of window
+   * content if moved after the underlying window paints.
+   */
+#if defined(XP_WIN)
+  if (pluginsUpdatedFlag) {
+    mPluginUpdateResponsePending = true;
+    return;
+  }
+#endif
+
   // We do not support plugins in local content. When switching tabs
   // to local pages, hide every plugin associated with the window.
-  if (!mCompositionManager->HasRemoteContent()) {
+  if (!hasRemoteContent && BrowserTabsRemoteAutostart() &&
+      mCachedPluginData.Length()) {
     unused << SendHideAllPlugins((uintptr_t)GetWidget());
+    mCachedPluginData.Clear();
+#if defined(XP_WIN)
+    // Wait for confirmation the hide operation is complete.
+    mPluginUpdateResponsePending = true;
+    return;
+#endif
   }
 #endif
 
@@ -1129,6 +1177,20 @@ CompositorParent::CompositeToTarget(DrawTarget* aTarget, const gfx::IntRect* aRe
   profiler_tracing("Paint", "Composite", TRACING_INTERVAL_END);
 }
 
+bool
+CompositorParent::RecvRemotePluginsReady()
+{
+#if defined(XP_WIN)
+  mPluginUpdateResponsePending = false;
+  ScheduleComposition();
+  return true;
+#else
+  NS_NOTREACHED("CompositorParent::RecvRemotePluginsReady calls "
+                "unexpected on this platform.");
+  return false;
+#endif
+}
+
 void
 CompositorParent::ForceComposeToTarget(DrawTarget* aTarget, const gfx::IntRect* aRect)
 {
@@ -1744,6 +1806,7 @@ public:
                                       const nsTArray<ScrollableLayerGuid>& aTargets) override;
 
   virtual AsyncCompositionManager* GetCompositionManager(LayerTransactionParent* aParent) override;
+  virtual bool RecvRemotePluginsReady()  override { return false; }
 
   void DidComposite(uint64_t aId,
                     TimeStamp& aCompositeStart,

gfx/layers/ipc/CompositorParent.h

@@ -386,9 +386,15 @@ public:
    * Calculates and requests the main thread update plugin positioning, clip,
    * and visibility via ipc.
    */
-  void UpdatePluginWindowState(uint64_t aId);
+  bool UpdatePluginWindowState(uint64_t aId);
 #endif
 
+  /**
+   * Main thread response for a plugin visibility request made by the
+   * compositor thread.
+   */
+  virtual bool RecvRemotePluginsReady() override;
+
   /**
    * Used by the profiler to denote when a vsync occured
    */
@@ -485,6 +491,11 @@ protected:
   nsIntRegion mPluginsLayerVisibleRegion;
   nsTArray<PluginWindowData> mCachedPluginData;
 #endif
+#if defined(XP_WIN)
+  // indicates if we are currently waiting on a plugin update confirmation.
+  // When this is true, composition is currently on hold.
+  bool mPluginUpdateResponsePending;
+#endif
 
   DISALLOW_EVIL_CONSTRUCTORS(CompositorParent);
 };

gfx/layers/ipc/PCompositor.ipdl

@@ -82,6 +82,11 @@ child:
   async ClearCachedResources(uint64_t id);
 
 parent:
+  /**
+   * Confirmation callback for UpdatePluginConfigurations and HideAllPlugins.
+   */
+  async RemotePluginsReady();
+
   // Child sends the parent a request for fill ratio numbers.
   async RequestOverfill();