Update docs and trunk dirs if they exist overriding any local merge conflicts.

Created to fix bug http://code.google.com/p/skia/issues/detail?id=710 :
housekeeping buildbot: conflict in UpdateDoxygen step.

git-svn-id: http://skia.googlecode.com/svn/trunk@4640 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/update-doxygen.sh b/tools/update-doxygen.sh
index 5965064..5474b17 100755
--- a/tools/update-doxygen.sh
+++ b/tools/update-doxygen.sh
@@ -20,8 +20,17 @@
 
 mkdir -p $DOXYGEN_TEMPDIR
 cd $DOXYGEN_TEMPDIR
-svn checkout http://skia.googlecode.com/svn/trunk  # read-only
-svn checkout https://skia-autogen.googlecode.com/svn/docs  # writeable
+
+if [ -d "trunk" ]; then
+  svn update --accept theirs-full trunk
+else
+  svn checkout http://skia.googlecode.com/svn/trunk  # read-only
+fi
+if [ -d "docs" ]; then
+  svn update --accept theirs-full docs
+else
+  svn checkout https://skia-autogen.googlecode.com/svn/docs  # writeable
+fi
 
 # Run Doxygen.
 cd trunk