From af23265853fe95f3d04aa8681b98f1e656df2925 Mon Sep 17 00:00:00 2001
From: Nicholas Cameron <ncameron@mozilla.com>
Date: Fri, 9 Aug 2013 11:30:18 +1200
Subject: [PATCH] Bug 901404. Support Azure with single buffered thebes layers.
 r=mattwoodrow

---
 gfx/layers/ThebesLayerBuffer.h      | 24 ++++++++++++++
 gfx/layers/client/ContentClient.cpp | 49 ++++++++++++++++++++---------
 2 files changed, 58 insertions(+), 15 deletions(-)

diff --git a/gfx/layers/ThebesLayerBuffer.h b/gfx/layers/ThebesLayerBuffer.h
index f8f6c48c9e9..2b76bf0b631 100644
--- a/gfx/layers/ThebesLayerBuffer.h
+++ b/gfx/layers/ThebesLayerBuffer.h
@@ -245,6 +245,8 @@ public:
    */
   gfxASurface* GetBuffer() { return mBuffer; }
   gfxASurface* GetBufferOnWhite() { return mBufferOnWhite; }
+  gfx::DrawTarget* GetDTBuffer() { return mDTBuffer; }
+  gfx::DrawTarget* GetDTBufferOnWhite() { return mDTBufferOnWhite; }
 
   /**
    * Complete the drawing operation. The region to draw must have been
@@ -271,11 +273,33 @@ protected:
   already_AddRefed<gfxASurface>
   SetBufferOnWhite(gfxASurface* aBuffer)
   {
+    MOZ_ASSERT(!SupportsAzureContent());
     nsRefPtr<gfxASurface> tmp = mBufferOnWhite.forget();
     mBufferOnWhite = aBuffer;
     return tmp.forget();
   }
 
+  TemporaryRef<gfx::DrawTarget>
+  SetDTBuffer(gfx::DrawTarget* aBuffer,
+            const nsIntRect& aBufferRect, const nsIntPoint& aBufferRotation)
+  {
+    MOZ_ASSERT(SupportsAzureContent());
+    RefPtr<gfx::DrawTarget> tmp = mDTBuffer.forget();
+    mDTBuffer = aBuffer;
+    mBufferRect = aBufferRect;
+    mBufferRotation = aBufferRotation;
+    return tmp.forget();
+  }
+
+  TemporaryRef<gfx::DrawTarget>
+  SetDTBufferOnWhite(gfx::DrawTarget* aBuffer)
+  {
+    MOZ_ASSERT(SupportsAzureContent());
+    RefPtr<gfx::DrawTarget> tmp = mDTBufferOnWhite.forget();
+    mDTBufferOnWhite = aBuffer;
+    return tmp.forget();
+  }
+
   /**
    * Set the texture client only.  This is used with surfaces that
    * require explicit lock/unlock, which |aClient| is used to do on
diff --git a/gfx/layers/client/ContentClient.cpp b/gfx/layers/client/ContentClient.cpp
index 5c2ae2bb57e..2679b2d1e52 100644
--- a/gfx/layers/client/ContentClient.cpp
+++ b/gfx/layers/client/ContentClient.cpp
@@ -545,23 +545,42 @@ ContentClientSingleBuffered::SyncFrontBufferToBackBuffer()
     return;
   }
 
-  gfxASurface* backBuffer = GetBuffer();
-  if (!backBuffer && mDeprecatedTextureClient) {
-    backBuffer = mDeprecatedTextureClient->LockSurface();
+  if (SupportsAzureContent()) {
+    DrawTarget* backBuffer = GetDTBuffer();
+    if (!backBuffer && mDeprecatedTextureClient) {
+      backBuffer = mDeprecatedTextureClient->LockDrawTarget();
+    }
+
+    RefPtr<DrawTarget> oldBuffer;
+    oldBuffer = SetDTBuffer(backBuffer,
+                            mBufferRect,
+                            mBufferRotation);
+
+    backBuffer = GetDTBufferOnWhite();
+    if (!backBuffer && mDeprecatedTextureClientOnWhite) {
+      backBuffer = mDeprecatedTextureClientOnWhite->LockDrawTarget();
+    }
+
+    oldBuffer = SetDTBufferOnWhite(backBuffer);
+  } else {
+    gfxASurface* backBuffer = GetBuffer();
+    if (!backBuffer && mDeprecatedTextureClient) {
+      backBuffer = mDeprecatedTextureClient->LockSurface();
+    }
+
+    nsRefPtr<gfxASurface> oldBuffer;
+    oldBuffer = SetBuffer(backBuffer,
+                          mBufferRect,
+                          mBufferRotation);
+
+    backBuffer = GetBufferOnWhite();
+    if (!backBuffer && mDeprecatedTextureClientOnWhite) {
+      backBuffer = mDeprecatedTextureClientOnWhite->LockSurface();
+    }
+
+    oldBuffer = SetBufferOnWhite(backBuffer);
   }
 
-  nsRefPtr<gfxASurface> oldBuffer;
-  oldBuffer = SetBuffer(backBuffer,
-                        mBufferRect,
-                        mBufferRotation);
-
-  backBuffer = GetBufferOnWhite();
-  if (!backBuffer && mDeprecatedTextureClientOnWhite) {
-    backBuffer = mDeprecatedTextureClientOnWhite->LockSurface();
-  }
-
-  oldBuffer = SetBufferOnWhite(backBuffer);
-
   mIsNewBuffer = false;
   mFrontAndBackBufferDiffer = false;
 }