disable some poppler tests due to flakiness (see bug)

expectations/gm/Test-Mac10.6-MacMini4.1-GeForce320M-x86_64-Release/expected-results.json

 {
   "actual-results": {
     "failed": null, 
     "failure-ignored": null, 
     "no-comparison": null, 
     "succeeded": null
   }, 
   "expected-results": {
     "3x3bitmaprect_565.png": {
       "allowed-digests": [
@@ skipping 7822 matching lines @@
           "bitmap-64bitMD5", 
           3557127310706663802
         ]
       ], 
       "ignore-failure": false
     }, 
     "imageblur_pdf-poppler.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          2042594177985516213
+          18221340919266374351

[epoger, 2013/09/19 06:04:01]

rebaselined as follows:

tools/rebaseline.py --bugs 1643 --ignore-failure --unreviewed --configs
pdf-poppler --tests imageblur imagemagnifier giantbitmap_clamp_bilerp_scale

I guess the giantbitmap_clamp_bilerp_scale failure I noted in
https://code.google.com/p/skia/issues/detail?id=1643#c3 already "flaked back to
success".

         ]
       ], 
       "bugs": [
-        1578
+        1643
       ], 
+      "ignore-failure": true, 
       "reviewed-by-human": false
     }, 
     "imagefiltersbase_565.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           12131937448726798610
         ]
       ], 
       "ignore-failure": false
@@ skipping 168 matching lines @@
       ], 
       "bugs": [
         1578
       ], 
       "reviewed-by-human": false
     }, 
     "imagemagnifier_pdf-poppler.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
-          2042594177985516213
+          18221340919266374351
         ]
       ], 
       "bugs": [
-        1578
+        1643
       ], 
+      "ignore-failure": true, 
       "reviewed-by-human": false
     }, 
     "internal_links_565.png": {
       "allowed-digests": [
         [
           "bitmap-64bitMD5", 
           11965002661414154194
         ]
       ], 
       "bugs": [
@@ skipping 4491 matching lines @@
           10424380103329133154
         ]
       ], 
       "bugs": [
         1578
       ], 
       "reviewed-by-human": false
     }
   }
 }