Fix onBeforeSendHeaders regression: we were sending {name: name} for every

chrome/test/data/extensions/api_test/webrequest/events/test.html

 <script>
 var getURL = chrome.extension.getURL;
 var deepEq = chrome.test.checkDeepEq;
 var expectedEventData;
 var capturedEventData;
 var expectedEventOrder;
 var tabId;
 var eventsCaptured;
 
 // PORT will be changed to the port of the test server.
@@ skipping 86 matching lines @@
       chrome.test.assertTrue(positions[previousLabel] < positions[label],
           "Event " + previousLabel + " is supposed to arrive before " +
           label + ".");
       previousLabel = label;
     });
   });
 
   eventsCaptured();
 }
 
+// Simple check to see that we have a User-Agent header, and that it contains
+// an expected value. This is a basic check that the request headers are valid.
+function checkUserAgent(headers) {
+  for (var i in headers) {
+    if (headers[i].name.toLowerCase() == "user-agent")
+      return headers[i].value.toLowerCase().indexOf("chrome") != -1;
+  }
+  return false;
+}
+
 function captureEvent(name, details) {
   // Ignore system-level requests like safebrowsing updates and favicon fetches
   // since they are unpredictable.
   if (details.tabId == -1 || details.type == "other" ||
       details.url.match(/\/favicon.ico$/) ||
       details.url.match(/https:\/\/dl.google.com/))
     return;
 
   // Pull the extra per-event options out of the expected data. These let
   // us specify special return values per event.
   var currentIndex = capturedEventData.length;
   var extraOptions;
   if (expectedEventData.length > currentIndex) {
     retval = expectedEventData[currentIndex].retval;
   }
 
   delete details.requestId;
   delete details.timeStamp;
   if (details.requestHeaders) {
-    details.requestHeadersExist = true;
+    details.requestHeadersValid = checkUserAgent(details.requestHeaders);
     delete details.requestHeaders;
   }
   if (details.responseHeaders) {
     details.responseHeadersExist = true;
     delete details.responseHeaders;
   }
 
   // find |details| in expectedEventData
   var found = false;
   var label = undefined;
@@ skipping 119 matching lines @@
             method: "GET",
             tabId: tabId,
             type: "main_frame",
             url: URL_HTTP_SIMPLE_LOAD_REDIRECT
           }
         },
         { label: "onBeforeSendHeaders-1",
           event: "onBeforeSendHeaders",
           details: {
             url: URL_HTTP_SIMPLE_LOAD_REDIRECT,
-            requestHeadersExist: true
+            requestHeadersValid: true
           }
         },
         { label: "onRequestSent-1",
           event: "onRequestSent",
           details: {
             url: URL_HTTP_SIMPLE_LOAD_REDIRECT,
             ip: "127.0.0.1",
-            requestHeadersExist: true
+            requestHeadersValid: true
           }
         },
         { label: "onBeforeRedirect",
           event: "onBeforeRedirect",
           details: {
             url: URL_HTTP_SIMPLE_LOAD_REDIRECT,
             redirectUrl: URL_HTTP_SIMPLE_LOAD,
             statusCode: 301,
             responseHeadersExist: true,
             statusLine: "HTTP/1.0 301 Moved Permanently"
           }
         },
         { label: "onBeforeRequest-2",
           event: "onBeforeRequest",
           details: {
             method: "GET",
             tabId: tabId,
             type: "main_frame",
             url: URL_HTTP_SIMPLE_LOAD
           }
         },
         { label: "onBeforeSendHeaders-2",
           event: "onBeforeSendHeaders",
           details: {
             url: URL_HTTP_SIMPLE_LOAD,
-            requestHeadersExist: true
+            requestHeadersValid: true
           }
         },
         { label: "onRequestSent-2",
           event: "onRequestSent",
           details: {
             url: URL_HTTP_SIMPLE_LOAD,
             ip: "127.0.0.1",
-            requestHeadersExist: true
+            requestHeadersValid: true
           }
         },
         { label: "onResponseStarted",
           event: "onResponseStarted",
           details: {
             url: URL_HTTP_SIMPLE_LOAD,
             statusCode: 200,
             responseHeadersExist: true,
             statusLine: "HTTP/1.0 200 OK",
           }
@@ skipping 341 matching lines @@
       });
       chrome.tabs.executeScript(tabId,
         {
           code: "chrome.extension.sendRequest(" +
               "{pass: document.body.innerText.indexOf('FoobarUA') >= 0});"
         });
     });
   },
 ]);
 </script>