Enforce the 'requirements' field in manifests.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index facfede3166c764e78aef4fbb898d565a8250c95..f797274eb47e93d31d0531a43a5d9794641279a7 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -4549,6 +4549,18 @@ Update checks have repeatedly failed for the extension "<ph name="EXTENSION_NAME
       <message name="IDS_EXTENSION_CANT_DOWNGRADE_VERSION" desc="Error message when a user tries to install an extension with a lower version that a version that it already installed.">
         Attempted to downgrade extension.
       </message>
+      <message name="IDS_EXTENSION_WEBGL_NOT_SUPPORTED" desc="Error message when an extension has a requirement for WebGL that the system does not support.">
+        WebGL is not supported.
+      </message>
+      <message name="IDS_EXTENSION_CSS3D_NOT_SUPPORTED" desc="Error message when an extension has a requirement for CSS3d that the system does not support.">
+        CSS3d is not supported.
+      </message>
+      <message name="IDS_EXTENSION_PLUGINS_NOT_SUPPORTED" desc="Error message when an extension has a requirement for plugins that the system does not support.">
+        Plugins are not supported.
+      </message>
+      <message name="IDS_EXTENSION_REQUIREMENT_DISABLE" desc="Error message when an extension was disabled due to unsupported requirements and the user attempts to re-enable the extension.">
+        Cannot enable, not all requirements are met.

[Aaron Boodman, 2012/08/21 23:04:21]

It would be better to show the specific requirement that was not met.

[eaugusti, 2012/08/24 19:30:52]

Ok. To do this we will need a value in the prefs. I am going to pass around a
bitmask instead of the localized strings. Then we can just use a utility
function to pull the localized strings out of the bitmask.

+      </message>
       <message name="IDS_EXTENSION_CANT_INSTALL_BLACKLISTED" desc="Error message when a user tries to install an extension that is blacklisted.">
         This extension is blacklisted.
       </message>