sample only 1% of pdf exceptions due to volume of requests to sentry

services/web/public/coffee/ide/pdfng/directives/pdfRenderer.coffee

@@ -145,7 +145,7 @@ define [
 
 				timedOut = false
 				timer = $timeout () =>
-					Raven?.captureMessage?('pdfng page load timed out after ' + @PAGE_LOAD_TIMEOUT + 'ms')
+					Raven?.captureMessage?('pdfng page load timed out after ' + @PAGE_LOAD_TIMEOUT + 'ms (1% sample)') if Math.random() < 0.01
 					# console.log 'page load timed out', pagenum
 					timedOut = true
 					clearTimeout(spinTimer)
@@ -246,7 +246,7 @@ define [
 				timedOut = false
 
 				timer = $timeout () =>
-					Raven?.captureMessage?('pdfng page render timed out after ' + @PAGE_RENDER_TIMEOUT + 'ms')
+					Raven?.captureMessage?('pdfng page render timed out after ' + @PAGE_RENDER_TIMEOUT + 'ms (1% sample)') if Math.random() < 0.01
 					# console.log 'page render timed out', pagenum
 					timedOut = true
 					result.cancel()

services/web/public/coffee/ide/pdfng/directives/pdfViewer.coffee

@@ -38,7 +38,7 @@ define [
 				loadedCallback: () ->
 					$scope.$emit 'loaded'
 				errorCallback: (error) ->
-					Raven?.captureMessage?('pdfng error ' + error)
+					Raven?.captureMessage?('pdfng error ' + error + ' (1% sample)') if Math.random() < 0.01
 					$scope.$emit 'pdf:error', error
 				pageSizeChangeCallback: (pageNum, deltaH) ->
 					$scope.$broadcast 'pdf:page:size-change', pageNum, deltaH