Add alpha channel for the EGLConfig

If the alpha channel is not assigned,the framebuffer will be Opaque.
And it will mask the underlying video and make the video invisible
when play video width mediaplayer

cherry-picked from AOSP master

Issue: b/36025630
Test: clean build and boot PixelC
Change-Id: If756ad2aaa789f6ddb178333b3e8854f52c8eac3

diff --git a/services/surfaceflinger/RenderEngine/RenderEngine.cpp b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
index e3dbecc..7564269 100644 (file)
--- a/services/surfaceflinger/RenderEngine/RenderEngine.cpp
+++ b/services/surfaceflinger/RenderEngine/RenderEngine.cpp
@@ -382,6 +382,7 @@ static status_t selectEGLConfig(EGLDisplay display, EGLint format,
         attribs[EGL_RED_SIZE]                   = 8;
         attribs[EGL_GREEN_SIZE]                 = 8;
         attribs[EGL_BLUE_SIZE]                  = 8;
+        attribs[EGL_ALPHA_SIZE]                 = 8;
         wantedAttribute                         = EGL_NONE;
         wantedAttributeValue                    = EGL_NONE;
     } else {