Remove C++11 related warning

Change-Id: I250ff7bd0ea49908e11b14c995d77312cd09a8b4
diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index c7a2014..ca9a38e 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -183,14 +183,7 @@
 
     updateLayers();
 
-    // If we know that we are going to redraw the entire framebuffer,
-    // perform a discard to let the driver know we don't need to preserve
-    // the back buffer for this frame.
-    if (mCaches.extensions.hasDiscardFramebuffer() &&
-            left <= 0.0f && top <= 0.0f && right >= mWidth && bottom >= mHeight) {
-        const GLenum attachments[] = { getTargetFbo() == 0 ? GL_COLOR_EXT : GL_COLOR_ATTACHMENT0 };
-        glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1, attachments);
-    }
+    discardFramebuffer(left, top, right, bottom);
 
     syncState();
 
@@ -207,6 +200,18 @@
     return clear(left, top, right, bottom, opaque);
 }
 
+void OpenGLRenderer::discardFramebuffer(float left, float top, float right, float bottom) {
+    // If we know that we are going to redraw the entire framebuffer,
+    // perform a discard to let the driver know we don't need to preserve
+    // the back buffer for this frame.
+    if (mCaches.extensions.hasDiscardFramebuffer() &&
+            left <= 0.0f && top <= 0.0f && right >= mWidth && bottom >= mHeight) {
+        const GLenum attachments[] = { getTargetFbo() == 0 ? (const GLenum) GL_COLOR_EXT :
+                (const GLenum) GL_COLOR_ATTACHMENT0 };
+        glDiscardFramebufferEXT(GL_FRAMEBUFFER, 1, attachments);
+    }
+}
+
 status_t OpenGLRenderer::clear(float left, float top, float right, float bottom, bool opaque) {
     if (!opaque) {
         mCaches.enableScissor();