Add code generation for ConditionalFeatures bindings code

third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForCore.cpp.tmpl

Index: third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForCore.cpp.tmpl
diff --git a/third_party/WebKit/Source/bindings/core/v8/ConditionalFeaturesForCore.cpp b/third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForCore.cpp.tmpl
similarity index 73%
rename from third_party/WebKit/Source/bindings/core/v8/ConditionalFeaturesForCore.cpp
rename to third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForCore.cpp.tmpl
index 986b764e20eb7f68c5a8b279fbf66de4a18c7311..4f60264e41f66c952517ac31123e97541b1b674f 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ConditionalFeaturesForCore.cpp
+++ b/third_party/WebKit/Source/bindings/templates/ConditionalFeaturesForCore.cpp.tmpl
@@ -4,16 +4,9 @@
 
 #include "bindings/core/v8/ConditionalFeaturesForCore.h"
 
-#include "bindings/core/v8/V8Document.h"
-#include "bindings/core/v8/V8HTMLLinkElement.h"
-#include "bindings/core/v8/V8Navigator.h"
-#include "bindings/core/v8/V8Window.h"
-#include "core/context_features/ContextFeatureSettings.h"
-#include "core/dom/ExecutionContext.h"
-#include "core/frame/Frame.h"
-#include "core/origin_trials/OriginTrials.h"
-#include "platform/bindings/ConditionalFeatures.h"
-#include "platform/bindings/ScriptState.h"
+{% for include in includes %}
+#include "{{ include }}"
+{% endfor %}
 
 namespace blink {
 
@@ -31,14 +24,13 @@ void InstallConditionalFeaturesCore(const WrapperTypeInfo* wrapper_type_info,
   (*g_old_install_conditional_features_function)(
       wrapper_type_info, script_state, prototype_object, interface_object);
 
-  // TODO(iclelland): Generate all of this logic at compile-time, based on the
-  // configuration of origin trial enabled attributes and interfaces in IDL
-  // files. (crbug.com/615060)
   ExecutionContext* execution_context = ExecutionContext::From(script_state);
   if (!execution_context)
     return;
   v8::Isolate* isolate = script_state->GetIsolate();
   const DOMWrapperWorld& world = script_state->World();
+  // TODO(iclelland): Unify ContextFeatureSettings with the rest of the
+  // conditional features.
   if (wrapper_type_info == &V8Window::wrapperTypeInfo) {
     auto* settings = ContextFeatureSettings::From(
         execution_context,
@@ -49,37 +41,45 @@ void InstallConditionalFeaturesCore(const WrapperTypeInfo* wrapper_type_info,
       V8Window::installMojoJS(isolate, world, instance_object, prototype_object,
                               interface_object);
     }
-  } else if (wrapper_type_info == &V8HTMLLinkElement::wrapperTypeInfo) {
-    if (OriginTrials::linkServiceWorkerEnabled(execution_context)) {
-      V8HTMLLinkElement::installLinkServiceWorker(
+  }
+  {% for interface in installers_by_interface %}
+  if (wrapper_type_info == &{{ interface.class }}::wrapperTypeInfo) {
+    {% for installer in interface.installers %}

[chasej, 2017/07/11 20:12:31]

Will this code generation properly handle global objects? Specifically, it
doesn't declare/get the instance object, like in the Modules file below.
Probably best addressed by de-duplicating code (as in my comment below).

[iclelland, 2017/07/12 17:23:20]

That's a good point, we've never defined a trial interface directly on the core
members of a global, but it's a possibility that we should be prepared to
handle. I'll dedupe as much as possible between the two files. It should even be
possible to have a common core that both of them import, once the ContextFeature
code is removed.

[chasej, 2017/07/12 19:53:41]

Actually, the Long Task Observer trial required installing things on the Window
instance:
https://chromium.googlesource.com/chromium/src/+/82e2114b9d4b41b5d619e0a401b7...

I don't remember what was installed, but just pointing out this scenario is not
a hypothetical. If interested, could go back to see what the IDL looked like for
Long Task Observer.

Regardless, this code will now handle the scenario, so we're good.

+    if ({{ installer.condition }}(execution_context)) {
+      {{ installer.class }}::{{ installer.install_method }}(
           isolate, world, v8::Local<v8::Object>(), prototype_object,
           interface_object);
     }
+    {% endfor %}
   }
+  {% endfor %}
 }
 
 void InstallPendingConditionalFeatureCore(const String& feature,

[chasej, 2017/07/11 20:12:32]

Ditto. Should be "...ForCore" to be consistent with file name (and modules
version)?

[iclelland, 2017/07/12 17:23:20]

Yes, this was a holdover from the handwritten code. Thanks.

                                           const ScriptState* script_state) {
   (*g_old_install_pending_conditional_feature_function)(feature, script_state);
 
-  // TODO(iclelland): Generate all of this logic at compile-time, based on the
-  // configuration of origin trial enabled attributes and interfaces in IDL
-  // files. (crbug.com/615060)
+  {% if installers_by_feature %}
   v8::Local<v8::Object> prototype_object;
   v8::Local<v8::Function> interface_object;
   v8::Isolate* isolate = script_state->GetIsolate();
   const DOMWrapperWorld& world = script_state->World();
   V8PerContextData* context_data = script_state->PerContextData();
-  if (feature == "ForeignFetch") {
+  {% for feature in installers_by_feature %}
+  if (feature == "{{ feature.name }}") {
+    {% for installer in feature.installers %}
     if (context_data->GetExistingConstructorAndPrototypeForType(
-            &V8HTMLLinkElement::wrapperTypeInfo, &prototype_object,
+            &{{ installer.class }}::wrapperTypeInfo, &prototype_object,
             &interface_object)) {
-      V8HTMLLinkElement::installLinkServiceWorker(
+      {{ installer.class_or_partial }}::{{ installer.install_method }}(
           isolate, world, v8::Local<v8::Object>(), prototype_object,
           interface_object);
     }
+    {% endfor %}
     return;
   }
+  {% endfor %}
+  {% endif %}
 }
 
 void InstallConditionalFeaturesOnWindow(const ScriptState* script_state) {