Bug 1284721 - Flush CanvasRenderingContext2D's DrawTarget before hand…

…ing it off to the BufferProvider. r=lsalzman
dothq · Jul 8, 2016 · b51ed22 · b51ed22
1 parent ff42b19
commit b51ed22
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/dom/canvas/CanvasRenderingContext2D.cpp b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -904,9 +904,6 @@ class CanvasRenderingContext2DUserData : public LayerUserData {
     if (!context || !context->mTarget)
       return;
 
-    // Since SkiaGL default to store drawing command until flush
-    // We will have to flush it before present.
-    context->mTarget->Flush();
     context->ReturnTarget();
   }
 

diff --git a/gfx/layers/PersistentBufferProvider.cpp b/gfx/layers/PersistentBufferProvider.cpp
@@ -40,6 +40,11 @@ PersistentBufferProviderBasic::ReturnDrawTarget(already_AddRefed<gfx::DrawTarget
 {
   RefPtr<gfx::DrawTarget> dt(aDT);
   MOZ_ASSERT(mDrawTarget == dt);
+  if (dt) {
+    // Since SkiaGL default to storing drawing command until flush
+    // we have to flush it before present.
+    dt->Flush();
+  }
   return true;
 }
 
@@ -205,10 +210,12 @@ PersistentBufferProviderShared::ReturnDrawTarget(already_AddRefed<gfx::DrawTarge
 
   mBack->Unlock();
 
-  if (!mBuffer && mFront && !mFront->IsLocked()) {
-    mBuffer.swap(mFront);
+  if (mFront != mBack && !mBuffers.Contains(mFront)) {
+    mBuffers.AppendElement(mFront);
   }
 
+  // Make mFront point to the now realized back buffer. mFront is what the next
+  // transaction will pick up and send to the compositor.
   mFront = mBack;
 
   return true;