feat(config): Option to exclude test for specific capability

Add the option to exclude spec files for a specific capability.
This way you can ignore spec files for one capability only.
For example if the test is known to fail in the capability.

Closes angular#1230

docs/referenceConf.js

@@ -111,7 +111,7 @@ exports.config = {
     // Additional spec files to be run on this capability only.
     specs: ['spec/chromeOnlySpec.js'],
 
-    //Exclude spec files for this capability.
+    // Spec files to be excluded on this capability only.
     exclude: ['spec/doNotRunInChromeSpec.js']
   },
 

lib/taskScheduler.js

@@ -55,11 +55,11 @@ var TaskScheduler = function(config) {
       capabilitySpecs = capabilitySpecs.concat(capabilitySpecificSpecs);
     }
 
-    if(capability.exclude) {
+    if (capability.exclude) {
       var capabilitySpecExcludes = ConfigParser.resolveFilePatterns(
           capability.exclude, true, config.configDir);
       capabilitySpecs = ConfigParser.resolveFilePatterns(
-          capabilitySpecs).filter(function (path) {
+          capabilitySpecs).filter(function(path) {
               return capabilitySpecExcludes.indexOf(path) < 0;
           });
     }

spec/unit/taskScheduler_test.js

@@ -221,4 +221,26 @@ describe('the task scheduler', function() {
 
     expect(scheduler.numTasksRemaining()).toEqual(0);
   });
+
+  it('should exclude capability-specific specs', function() {
+    var toAdd = {
+        specs: [
+            'spec/unit/data/fakespecA.js',
+            'spec/unit/data/fakespecB.js'
+        ],
+        multiCapabilities: [{
+            'browserName': 'chrome',
+            exclude: 'spec/unit/data/fakespecB.js'
+        }]
+    };
+    var config = new ConfigParser().addConfig(toAdd).getConfig();
+    var scheduler = new TaskScheduler(config);
+
+    var task = scheduler.nextTask();
+    expect(task.capability.browserName).toEqual('chrome');
+    expect(task.specs.length).toEqual(1);
+
+    expect(scheduler.numTasksRemaining()).toEqual(0);
+  });
+
 });