Remove -rdynamic from the linux debug build.

Having -rdynamic breaks some plugins since it exports more symbols into
the dynamic symbol table than wanted. In particular, this breaks users of
ppapi's C++ wrappers. It was added to make StaceTraces resolve to symbols
on linux. But now we use the symbolize library from glog so it isn't needed
anymore.

BUG=52105
TEST=Compiles and StackTrace.* test in base_unittests will work.

Review URL: http://codereview.chromium.org/3119033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@56924 0039d316-1c4b-4281-b951-d872f2087c98

build/common.gypi

@@ -925,9 +925,6 @@
               # One can use '-gstabs' to enable building the debugging
               # information in STABS format for breakpad's dumpsyms.
             ],
-            'ldflags': [
-              '-rdynamic',  # Allows backtrace to resolve symbols.
-            ],
           },
           'Release_Base': {
             'variables': {