More fixes to make 32 bit Linux builds pass compile.

This is breaking after r295514 which enforces that every file listed in an isolate file exists.

BUG=414808
R=erg@chromium.org

Review URL: https://codereview.chromium.org/585673002

Cr-Commit-Position: refs/heads/master@{#295589}

chrome/browser_tests.isolate

@@ -84,6 +84,12 @@
         ],
         'isolate_dependency_untracked': [
           '../third_party/bidichecker/',
+        ],
+      },
+    }],
+    ['OS=="win" or (OS=="linux" and target_arch=="x64")', {
+      'variables': {
+        'isolate_dependency_tracked': [
           '<(PRODUCT_DIR)/lib64/',
         ],
       },

testing/chromoting/chromoting_integration_tests.isolate

@@ -19,12 +19,18 @@
           '../xvfb.py',
           '<(PRODUCT_DIR)/libffmpegsumo.so',
           '<(PRODUCT_DIR)/libosmesa.so',
-          '<(PRODUCT_DIR)/nacl_irt_x86_64.nexe',
           '<(PRODUCT_DIR)/xdisplaycheck<(EXECUTABLE_SUFFIX)',
         ],
       },
     }],
-     ['OS=="linux" or OS=="mac" or OS=="win"', {
+    ['OS=="linux" and target_arch=="x64"', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/nacl_irt_x86_64.nexe',
+        ],
+      },
+    }],
+    ['OS=="linux" or OS=="mac" or OS=="win"', {
       'variables': {
         'isolate_dependency_tracked': [
           '../test_env.py',