diff -r 000000000000 -r 6474c204b198 gfx/layers/basic/BasicThebesLayer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/basic/BasicThebesLayer.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,229 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 "BasicThebesLayer.h"
+#include <stdint.h>                     // for uint32_t
+#include "GeckoProfiler.h"              // for PROFILER_LABEL
+#include "ReadbackLayer.h"              // for ReadbackLayer, ReadbackSink
+#include "ReadbackProcessor.h"          // for ReadbackProcessor::Update, etc
+#include "RenderTrace.h"                // for RenderTraceInvalidateEnd, etc
+#include "BasicLayersImpl.h"            // for AutoMaskData, etc
+#include "gfxContext.h"                 // for gfxContext, etc
+#include "gfxRect.h"                    // for gfxRect
+#include "gfxUtils.h"                   // for gfxUtils
+#include "mozilla/gfx/2D.h"             // for DrawTarget
+#include "mozilla/gfx/BaseRect.h"       // for BaseRect
+#include "mozilla/gfx/Matrix.h"         // for Matrix
+#include "mozilla/gfx/Rect.h"           // for Rect, IntRect
+#include "mozilla/gfx/Types.h"          // for Float, etc
+#include "mozilla/layers/LayersTypes.h"
+#include "nsAutoPtr.h"                  // for nsRefPtr
+#include "nsCOMPtr.h"                   // for already_AddRefed
+#include "nsISupportsImpl.h"            // for gfxContext::Release, etc
+#include "nsPoint.h"                    // for nsIntPoint
+#include "nsRect.h"                     // for nsIntRect
+#include "nsTArray.h"                   // for nsTArray, nsTArray_Impl
+#include "AutoMaskData.h"
+#include "gfx2DGlue.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace layers {
+
+static nsIntRegion
+IntersectWithClip(const nsIntRegion& aRegion, gfxContext* aContext)
+{
+  gfxRect clip = aContext->GetClipExtents();
+  clip.RoundOut();
+  nsIntRect r(clip.X(), clip.Y(), clip.Width(), clip.Height());
+  nsIntRegion result;
+  result.And(aRegion, r);
+  return result;
+}
+
+void
+BasicThebesLayer::PaintThebes(gfxContext* aContext,
+                              Layer* aMaskLayer,
+                              LayerManager::DrawThebesLayerCallback aCallback,
+                              void* aCallbackData,
+                              ReadbackProcessor* aReadback)
+{
+  PROFILER_LABEL("BasicThebesLayer", "PaintThebes");
+  NS_ASSERTION(BasicManager()->InDrawing(),
+               "Can only draw in drawing phase");
+
+  nsTArray<ReadbackProcessor::Update> readbackUpdates;
+  if (aReadback && UsedForReadback()) {
+    aReadback->GetThebesLayerUpdates(this, &readbackUpdates);
+  }
+
+  float opacity = GetEffectiveOpacity();
+  CompositionOp effectiveOperator = GetEffectiveOperator(this);
+
+  if (!BasicManager()->IsRetained()) {
+    NS_ASSERTION(readbackUpdates.IsEmpty(), "Can't do readback for non-retained layer");
+
+    mValidRegion.SetEmpty();
+    mContentClient->Clear();
+
+    nsIntRegion toDraw = IntersectWithClip(GetEffectiveVisibleRegion(), aContext);
+
+    RenderTraceInvalidateStart(this, "FFFF00", toDraw.GetBounds());
+
+    if (!toDraw.IsEmpty() && !IsHidden()) {
+      if (!aCallback) {
+        BasicManager()->SetTransactionIncomplete();
+        return;
+      }
+
+      aContext->Save();
+
+      bool needsClipToVisibleRegion = GetClipToVisibleRegion();
+      bool needsGroup = opacity != 1.0 ||
+                        effectiveOperator != CompositionOp::OP_OVER ||
+                        aMaskLayer;
+      nsRefPtr<gfxContext> groupContext;
+      if (needsGroup) {
+        groupContext =
+          BasicManager()->PushGroupForLayer(aContext, this, toDraw,
+                                            &needsClipToVisibleRegion);
+        if (effectiveOperator != CompositionOp::OP_OVER) {
+          needsClipToVisibleRegion = true;
+        }
+      } else {
+        groupContext = aContext;
+      }
+      SetAntialiasingFlags(this, groupContext);
+      aCallback(this, groupContext, toDraw, DrawRegionClip::CLIP_NONE, nsIntRegion(), aCallbackData);
+      if (needsGroup) {
+        BasicManager()->PopGroupToSourceWithCachedSurface(aContext, groupContext);
+        if (needsClipToVisibleRegion) {
+          gfxUtils::ClipToRegion(aContext, toDraw);
+        }
+        AutoSetOperator setOptimizedOperator(aContext, ThebesOp(effectiveOperator));
+        PaintWithMask(aContext, opacity, aMaskLayer);
+      }
+
+      aContext->Restore();
+    }
+
+    RenderTraceInvalidateEnd(this, "FFFF00");
+    return;
+  }
+
+  if (BasicManager()->IsTransactionIncomplete())
+    return;
+
+  gfxRect clipExtents;
+  clipExtents = aContext->GetClipExtents();
+
+  // Pull out the mask surface and transform here, because the mask
+  // is internal to basic layers
+  AutoMoz2DMaskData mask;
+  SourceSurface* maskSurface = nullptr;
+  Matrix maskTransform;
+  if (GetMaskData(aMaskLayer, Point(), &mask)) {
+    maskSurface = mask.GetSurface();
+    maskTransform = mask.GetTransform();
+  }
+
+  if (!IsHidden() && !clipExtents.IsEmpty()) {
+    mContentClient->DrawTo(this, aContext->GetDrawTarget(), opacity,
+                           GetOperator(),
+                           maskSurface, &maskTransform);
+  }
+
+  for (uint32_t i = 0; i < readbackUpdates.Length(); ++i) {
+    ReadbackProcessor::Update& update = readbackUpdates[i];
+    nsIntPoint offset = update.mLayer->GetBackgroundLayerOffset();
+    nsRefPtr<gfxContext> ctx =
+      update.mLayer->GetSink()->BeginUpdate(update.mUpdateRect + offset,
+                                            update.mSequenceCounter);
+    if (ctx) {
+      NS_ASSERTION(opacity == 1.0, "Should only read back opaque layers");
+      ctx->Translate(gfxPoint(offset.x, offset.y));
+      mContentClient->DrawTo(this, ctx->GetDrawTarget(), 1.0,
+                             CompositionOpForOp(ctx->CurrentOperator()),
+                             maskSurface, &maskTransform);
+      update.mLayer->GetSink()->EndUpdate(ctx, update.mUpdateRect + offset);
+    }
+  }
+}
+
+void
+BasicThebesLayer::Validate(LayerManager::DrawThebesLayerCallback aCallback,
+                           void* aCallbackData)
+{
+  if (!mContentClient) {
+    // This client will have a null Forwarder, which means it will not have
+    // a ContentHost on the other side.
+    mContentClient = new ContentClientBasic();
+  }
+
+  if (!BasicManager()->IsRetained()) {
+    return;
+  }
+
+  uint32_t flags = 0;
+#ifndef MOZ_WIDGET_ANDROID
+  if (BasicManager()->CompositorMightResample()) {
+    flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
+  }
+  if (!(flags & RotatedContentBuffer::PAINT_WILL_RESAMPLE)) {
+    if (MayResample()) {
+      flags |= RotatedContentBuffer::PAINT_WILL_RESAMPLE;
+    }
+  }
+#endif
+  if (mDrawAtomically) {
+    flags |= RotatedContentBuffer::PAINT_NO_ROTATION;
+  }
+  PaintState state =
+    mContentClient->BeginPaintBuffer(this, flags);
+  mValidRegion.Sub(mValidRegion, state.mRegionToInvalidate);
+
+  if (DrawTarget* target = mContentClient->BorrowDrawTargetForPainting(state)) {
+    // The area that became invalid and is visible needs to be repainted
+    // (this could be the whole visible area if our buffer switched
+    // from RGB to RGBA, because we might need to repaint with
+    // subpixel AA)
+    state.mRegionToInvalidate.And(state.mRegionToInvalidate,
+                                  GetEffectiveVisibleRegion());
+    SetAntialiasingFlags(this, target);
+
+    RenderTraceInvalidateStart(this, "FFFF00", state.mRegionToDraw.GetBounds());
+
+    nsRefPtr<gfxContext> ctx = gfxContext::ContextForDrawTarget(target);
+    PaintBuffer(ctx,
+                state.mRegionToDraw, state.mRegionToDraw, state.mRegionToInvalidate,
+                state.mDidSelfCopy,
+                state.mClip,
+                aCallback, aCallbackData);
+    MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) PaintThebes", this));
+    Mutated();
+    ctx = nullptr;
+    mContentClient->ReturnDrawTargetToBuffer(target);
+
+    RenderTraceInvalidateEnd(this, "FFFF00");
+  } else {
+    // It's possible that state.mRegionToInvalidate is nonempty here,
+    // if we are shrinking the valid region to nothing. So use mRegionToDraw
+    // instead.
+    NS_WARN_IF_FALSE(state.mRegionToDraw.IsEmpty(),
+                     "No context when we have something to draw, resource exhaustion?");
+  }
+}
+
+already_AddRefed<ThebesLayer>
+BasicLayerManager::CreateThebesLayer()
+{
+  NS_ASSERTION(InConstruction(), "Only allowed in construction phase");
+  nsRefPtr<ThebesLayer> layer = new BasicThebesLayer(this);
+  return layer.forget();
+}
+
+}
+}