Bug 755084 Part 3: Move checks for whether to animate opacity and transforms on the compositor thread to nsLayoutUtils, and make them also check whether the compositor is actually running r=cjones,dbaron

gfx/layers/Makefile.in

@@ -31,16 +31,18 @@ EXPORTS = \
         BasicLayers.h \
         BasicTiledThebesLayer.h \
         BasicImplData.h \
+        CompositorParent.h \
         ImageLayers.h \
         Layers.h \
         LayersBackend.h \
         LayerManagerOGLShaders.h \
         LayerManagerOGL.h \
         LayerManagerOGLProgram.h \
-        ReadbackLayer.h \
         LayerSorter.h \
-        TexturePoolOGL.h \
+        ReadbackLayer.h \
+        ShadowLayersManager.h \
         SharedTextureImage.h \
+        TexturePoolOGL.h \
         $(NULL)
 
 CPPSRCS = \

layout/base/nsLayoutUtils.cpp

@@ -4,6 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "base/basictypes.h"
 #include "mozilla/Util.h"
 
 #include "nsLayoutUtils.h"
@@ -70,7 +71,7 @@
 #include "nsTextFrame.h"
 #include "nsFontFaceList.h"
 #include "nsFontInflationData.h"
-
+#include "CompositorParent.h"
 #include "nsSVGUtils.h"
 #include "nsSVGIntegrationUtils.h"
 #include "nsSVGForeignObjectFrame.h"
@@ -157,6 +158,36 @@ nsLayoutUtils::Are3DTransformsEnabled()
   return s3DTransformsEnabled;
 }
 
+bool
+nsLayoutUtils::AreOpacityAnimationsEnabled()
+{
+  static bool sAreOpacityAnimationsEnabled;
+  static bool sOpacityPrefCached = false;
+
+  if (!sOpacityPrefCached) {
+    sOpacityPrefCached = true;
+    Preferences::AddBoolVarCache(&sAreOpacityAnimationsEnabled,
+                                 "layers.offmainthreadcomposition.animate-opacity");
+  }
+
+  return sAreOpacityAnimationsEnabled && CompositorParent::CompositorLoop();
+}
+
+bool
+nsLayoutUtils::AreTransformAnimationsEnabled()
+{
+  static bool sAreTransformAnimationsEnabled;
+  static bool sTransformPrefCached = false;
+
+  if (!sTransformPrefCached) {
+    sTransformPrefCached = true;
+    Preferences::AddBoolVarCache(&sAreTransformAnimationsEnabled,
+                                 "layers.offmainthreadcomposition.animate-transform");
+  }
+
+  return sAreTransformAnimationsEnabled && CompositorParent::CompositorLoop();
+}
+
 bool
 nsLayoutUtils::UseBackgroundNearestFiltering()
 {

layout/base/nsLayoutUtils.h

@@ -1509,6 +1509,12 @@ public:
    */
   static bool Are3DTransformsEnabled();
 
+  /**
+   * Checks if off-main-thread transform and opacity animations are enabled.
+   */
+  static bool AreOpacityAnimationsEnabled();
+  static bool AreTransformAnimationsEnabled();
+
   /**
    * Checks if we should forcibly use nearest pixel filtering for the
    * background.

layout/style/AnimationCommon.cpp

@@ -9,6 +9,7 @@
 #include "nsStyleContext.h"
 #include "nsIFrame.h"
 #include "nsAnimationManager.h"
+#include "nsLayoutUtils.h"
 
 namespace mozilla {
 namespace css {
@@ -221,7 +222,7 @@ CommonElementAnimationData::CanAnimatePropertyOnCompositor(const dom::Element *a
 {
   nsIFrame* frame = aElement->GetPrimaryFrame();
   if (aProperty == eCSSProperty_opacity) {
-    return nsAnimationManager::CanAnimateOpacity();
+    return nsLayoutUtils::AreOpacityAnimationsEnabled();
   }
   if (aProperty == eCSSProperty_transform && !(frame &&
       frame->Preserves3D() &&
@@ -229,7 +230,7 @@ CommonElementAnimationData::CanAnimatePropertyOnCompositor(const dom::Element *a
     if (frame && frame->IsSVGTransformed()) {
       return false;
     }
-    return nsAnimationManager::CanAnimateTransform();
+    return nsLayoutUtils::AreTransformAnimationsEnabled();
   }
   return false;
 }

layout/style/nsAnimationManager.h

@@ -182,20 +182,6 @@ public:
     mKeyframesRules.Init(16); // FIXME: make infallible!
   }
 
-  static bool CanAnimateOpacity() {
-    static bool canAnimateOpacity =
-      mozilla::Preferences::GetBool("layers.offmainthreadcomposition.animate-opacity", false) &&
-      mozilla::Preferences::GetBool("layers.offmainthreadcomposition.enabled", false);
-    return canAnimateOpacity;
-  }
-
-  static bool CanAnimateTransform() {
-    static bool canAnimateTransform =
-      mozilla::Preferences::GetBool("layers.offmainthreadcomposition.animate-transform", false) &&
-      mozilla::Preferences::GetBool("layers.offmainthreadcomposition.enabled", false);
-    return canAnimateTransform;
-  }
-
   static ElementAnimations* GetAnimationsForCompositor(nsIContent* aContent,
                                                        nsCSSProperty aProperty)
   {