Fix scissor for functor invocation

Bug: 10677765
 enableScissor() must precede setScissorFromClip() as
 otherwise setScissorFromClip() doesn't do anything.
 Also make sure to call setScissorFromClip() if
 enableScissor() returns true as enableScissor() calls
 resetScissor() if the scissor state has changed.

Change-Id: I9226b20bb256c92066aae344e4e6407540b6eae9

libs/hwui/OpenGLRenderer.cpp

@@ -471,12 +471,14 @@ status_t OpenGLRenderer::callDrawGLFunction(Functor* functor, Rect& dirty) {
     info.height = getSnapshot()->height;
     getSnapshot()->transform->copyTo(&info.transform[0]);
 
+    bool dirtyClip = mDirtyClip;
     // setup GL state for functor
     if (mDirtyClip) {
-        setScissorFromClip();
         setStencilFromClip(); // can issue draws, so must precede enableScissor()/interrupt()
     }
-    mCaches.enableScissor();
+    if (mCaches.enableScissor() || dirtyClip) {
+        setScissorFromClip();
+    }
     interrupt();
 
     // call functor immediately after GL state setup