Set the compiler root directory for the Android NDK, merging two linker flags.

This change replaces -rpath-link and an -L linking flag with --sysroot, which sets the compiler root directory for all headers and libraries.

BUG=
TEST=

Review URL: http://codereview.chromium.org/8938003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@114216 0039d316-1c4b-4281-b951-d872f2087c98

build/common.gypi

@@ -2111,8 +2111,7 @@
             'conditions': [
               ['android_build_type==0', {
                 'ldflags': [
-                  '-Wl,-rpath-link=<(android_ndk_lib)',
-                  '-L<(android_ndk_lib)',
+                  '--sysroot=<(android_ndk_sysroot)',
                 ],
               }],
               # NOTE: The stlport header include paths below are specified in