mac: Add the flag "-gline-tables-only" to reduce dSYM size.

The dSYM for Google Chrome Framework has grown to be larger than 4GB. dsymutil
can't handle this. Reduce the amount of debug info output for official builds
of Google Chrome. On my local machine, the dSYM is 10x smaller.

BUG=479841

Review URL: https://codereview.chromium.org/1085843004

Cr-Original-Commit-Position: refs/heads/master@{#326445}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: c4fc98d94448349b8fcf3d0627a166c74caf7053

common.gypi

@@ -5208,6 +5208,15 @@
                         }, {  # asan != 0
                           'STRIPFLAGS': '-S',
                         }],
+                        ['branding=="Chrome" and buildtype=="Official"', {
+                          'OTHER_CFLAGS': [
+                            # The Google Chrome Framework dSYM generated by
+                            # dsymutil has grown larger than 4GB, which
+                            # dsymutil can't handle. Reduce the amount of debug
+                            # symbols.
+                            '-gline-tables-only',  # See http://crbug.com/479841
+                          ]
+                        }],
                       ],
                     },  # xcode_settings
                   },  # configuration "Release"