Bug 811924 - Center boot animation on black background. r=mwu

Change-Id: I110e75331fa5455c226a9b4d23748372ca9ccbe9
---
 widget/gonk/libdisplay/BootAnimation.cpp |   23 +++++++++++++++++++++--
 1 files changed, 21 insertions(+), 2 deletions(-)

widget/gonk/libdisplay/BootAnimation.cpp

@@ -524,8 +524,27 @@ AnimationThread(void *)
                     display->QueueBuffer(buf);
                     break;
                 }
-                memcpy(vaddr, frame.buf,
-                       frame.width * frame.height * frame.bytepp);
+
+                if (buf->height == frame.height && buf->width == frame.width) {
+                    memcpy(vaddr, frame.buf,
+                           frame.width * frame.height * frame.bytepp);
+                } else if (buf->height >= frame.height &&
+                           buf->width >= frame.width) {
+                    int startx = (buf->width - frame.width) / 2;
+                    int starty = (buf->height - frame.height) / 2;
+
+                    int src_stride = frame.width * frame.bytepp;
+                    int dst_stride = buf->stride * frame.bytepp;
+
+                    char *src = frame.buf;
+                    char *dst = (char *) vaddr + starty * dst_stride + startx * frame.bytepp;
+
+                    for (int i = 0; i < frame.height; i++) {
+                        memcpy(dst, src, src_stride);
+                        src += src_stride;
+                        dst += dst_stride;
+                    }
+                }
                 grmodule->unlock(grmodule, buf->handle);
 
                 gettimeofday(&tv2, nullptr);