revert the surface purgatory list and dependent changes.

6d0f6cb Revert "Fix [3513017] in lockscreen but showing empty launcher (live wallpaper) only"
6154412 Revert "partially fix [3306150] HTML5 video with H/W acceleration blackout (DO NOT MERGE)"
37c2a37 fix [3408713] Dialog window invisible sometimes

It looks like there is a surface leak, it's unclear where it is.
Without those reverts, this would cause a leak of the associated buffers
which is far more problematic. this change might hide the surface leak.

Bug: 4078032
Change-Id: Iedcda3ffcdd2f69d41047b5c3134c1e867ff90d7
diff --git a/services/surfaceflinger/LayerDim.cpp b/services/surfaceflinger/LayerDim.cpp
index 11f8feb..80cc52c 100644
--- a/services/surfaceflinger/LayerDim.cpp
+++ b/services/surfaceflinger/LayerDim.cpp
@@ -67,14 +67,8 @@
         const GLfloat alpha = s.alpha/255.0f;
         const uint32_t fbHeight = hw.getHeight();
         glDisable(GL_DITHER);
-
-        if (s.alpha == 0xFF) {
-            glDisable(GL_BLEND);
-        } else {
-            glEnable(GL_BLEND);
-            glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-        }
-
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
         glColor4f(0, 0, 0, alpha);
 
 #if defined(GL_OES_EGL_image_external)