Disable WebShare on platforms other than android.

third_party/WebKit/Source/build/scripts/templates/OriginTrials.cpp.tmpl

 {% from 'macros.tmpl' import license %}
 {{license()}}
 
 #include "core/origin_trials/OriginTrials.h"
 
 #include "core/origin_trials/OriginTrialContext.h"
 #include "platform/RuntimeEnabledFeatures.h"
 
 namespace blink {
 
 {% for feature in features %}
 {% if feature.origin_trial_feature_name %}
 
 bool OriginTrials::{{feature.first_lowered_name}}Enabled(ExecutionContext* executionContext) {
     if (RuntimeEnabledFeatures::{{feature.first_lowered_name}}Enabled())
         return true;
+{% if feature.origin_trial_os_whitelist %}
+#if
+{%- for os in feature.origin_trial_os_whitelist %}
+{%- if not loop.first %} ||{% endif %}
+ defined(OS_{{os | upper}})
+{%- endfor %}
+{% endif %}
+
     OriginTrialContext* context = OriginTrialContext::from(executionContext, OriginTrialContext::DontCreateIfNotExists);
     return context && context->isFeatureEnabled("{{feature.origin_trial_feature_name}}");
+{% if feature.origin_trial_os_whitelist %}
+#else
+    return false;
+#endif
+{% endif %}
 }
 
 {% endif %}
 {% endfor %}
 
 } // namespace blink