Remove support for the keygen tag

chrome/app/theme/theme_resources.grd

Index: chrome/app/theme/theme_resources.grd
diff --git a/chrome/app/theme/theme_resources.grd b/chrome/app/theme/theme_resources.grd
index 868e023a01f231013dac6c0dac364cb5536b4c08..d02514e48c422d3a085e9191dfea020aa83c1f77 100644
--- a/chrome/app/theme/theme_resources.grd
+++ b/chrome/app/theme/theme_resources.grd
@@ -32,7 +32,6 @@
       <structure type="chrome_scaled_image" name="IDR_ALLOWED_FULLSCREEN" file="common/allowed_fullscreen.png" />
       <structure type="chrome_scaled_image" name="IDR_ALLOWED_IMAGES" file="common/allowed_images.png" />
       <structure type="chrome_scaled_image" name="IDR_ALLOWED_JAVASCRIPT" file="common/allowed_script.png" />
-      <structure type="chrome_scaled_image" name="IDR_ALLOWED_KEYGEN" file="common/allowed_keygen.png" />
       <structure type="chrome_scaled_image" name="IDR_ALLOWED_LOCATION" file="common/allowed_location.png" />
       <structure type="chrome_scaled_image" name="IDR_ALLOWED_MIC" file="common/allowed_mic.png" />
       <structure type="chrome_scaled_image" name="IDR_ALLOWED_MIDI_SYSEX" file="common/allowed_midi.png" />
@@ -87,7 +86,6 @@
       <structure type="chrome_scaled_image" name="IDR_BLOCKED_EXTENSION_SCRIPT" file="common/blocked_extension_script.png" />
       <structure type="chrome_scaled_image" name="IDR_BLOCKED_IMAGES" file="common/blocked_images.png" />
       <structure type="chrome_scaled_image" name="IDR_BLOCKED_JAVASCRIPT" file="common/blocked_script.png" />
-      <structure type="chrome_scaled_image" name="IDR_BLOCKED_KEYGEN" file="common/blocked_keygen.png" />
       <structure type="chrome_scaled_image" name="IDR_BLOCKED_LOCATION" file="common/blocked_location.png" />
       <structure type="chrome_scaled_image" name="IDR_BLOCKED_MIC" file="common/blocked_mic.png" />
       <structure type="chrome_scaled_image" name="IDR_BLOCKED_MIDI_SYSEX" file="common/blocked_midi.png" />