pdfviewer: enable pdfviewer to run with gm in one bot

tools/tests/factory_configuration/expected/Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Release-Trybot

Index: tools/tests/factory_configuration/expected/Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Release-Trybot
===================================================================
--- tools/tests/factory_configuration/expected/Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Release-Trybot	(revision 12085)
+++ tools/tests/factory_configuration/expected/Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Release-Trybot	(working copy)
@@ -55,6 +55,7 @@
     ],
     '_gyp_defines': {
         'skia_arch_width': '64',
+        'skia_run_pdfviewer_in_gm': '1',
         'skia_warnings_as_errors': '0',
     },
     '_make_flags': [],
@@ -390,7 +391,7 @@
                     '--bench_pictures_cfg',
                     'default',
                     '--gyp_defines',
-                    'skia_arch_width=64 skia_warnings_as_errors=0',
+                    'skia_arch_width=64 skia_warnings_as_errors=0 skia_run_pdfviewer_in_gm=1',
                     '--flavor',
                     'default',
                 ],
@@ -451,7 +452,7 @@
                     '--target',
                     'most',
                     '--gyp_defines',
-                    'skia_arch_width=64 skia_warnings_as_errors=0',
+                    'skia_arch_width=64 skia_warnings_as_errors=0 skia_run_pdfviewer_in_gm=1',
                     '--flavor',
                     'default',
                 ],
@@ -569,7 +570,7 @@
                     '--target',
                     'most',
                     '--gyp_defines',
-                    'skia_arch_width=64 skia_warnings_as_errors=0',
+                    'skia_arch_width=64 skia_warnings_as_errors=0 skia_run_pdfviewer_in_gm=1',
                     '--flavor',
                     'default',
                 ],
@@ -687,7 +688,7 @@
                     '--target',
                     'most',
                     '--gyp_defines',
-                    'skia_arch_width=64 skia_warnings_as_errors=0',
+                    'skia_arch_width=64 skia_warnings_as_errors=0 skia_run_pdfviewer_in_gm=1',
                     '--flavor',
                     'default',
                 ],