Enforce the 'requirements' field in manifests.

chrome/browser/extensions/requirements_provider.cc

Index: chrome/browser/extensions/requirements_provider.cc
diff --git a/chrome/browser/extensions/requirements_provider.cc b/chrome/browser/extensions/requirements_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..510307721272dae61245ba012f26bc53e8c2e38e
--- /dev/null
+++ b/chrome/browser/extensions/requirements_provider.cc
@@ -0,0 +1,173 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/extensions/requirements_provider.h"
+
+#include "base/bind.h"
+#include "base/string16.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/gpu_feature_checker.h"
+#include "chrome/common/extensions/extension_manifest_constants.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/extensions/manifest.h"
+#include "content/public/common/gpu_feature_type.h"
+
+namespace keys = extension_manifest_keys;
+
+namespace {
+
+const char* kWebGlError = "WebGL is not supported";
+const char* kCSS3dError = "CSS3d is not supported";
+#if defined(OS_CHROMEOS)
+const char* kPluginsError = "Plugins are not supported";
+#endif
+
+}  // namespace
+
+namespace extensions {
+
+RequirementsProvider::RequirementsProvider()
+    : ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
+}
+
+RequirementsProvider::~RequirementsProvider() {
+  weak_factory_.InvalidateWeakPtrs();
+}
+
+bool RequirementsProvider::Supports(const Extension* extension,
+                                    std::list<string16>* errors, bool* async,
+                                    ExtensionService* service) {
+  *async = false;
+  errors->clear();
+  DictionaryValue* requirements_value = NULL;
+  extension->manifest()->GetDictionary(keys::kRequirements,
+                                       &requirements_value);
+  if (!requirements_value)
+    return true;
+
+  for (DictionaryValue::key_iterator it = requirements_value->begin_keys();
+       it != requirements_value->end_keys(); ++it) {
+    DictionaryValue* requirement_value;
+    requirements_value->GetDictionaryWithoutPathExpansion(
+        *it, &requirement_value);
+    if (!requirement_value)
+      continue;
+
+    if (*it == "plugins") {
+#if defined(OS_CHROMEOS)
+      errors->push_back(ASCIIToUTF16(kPluginsError));
+#endif
+    } else if (*it == "3D") {
+      ListValue* features;
+      requirement_value->GetListWithoutPathExpansion("features", &features);
+      if (!features)
+        continue;
+      std::string feature;
+      base::ListValue::iterator it;
+      for (it = features->begin(); it != features->end(); ++it) {
+        if ((*it)->GetAsString(&feature)) {
+          if (feature == "webgl") {
+            if (checked_for_webgl_) {
+              if (!webgl_supported_)
+                errors->push_back(ASCIIToUTF16(kWebGlError));
+            } else {
+              *async = true;
+              // If the check is not ongoing, request one.
+              if (!webgl_checker_.get()) {
+                webgl_checker_ = new GPUFeatureChecker(
+                    content::GPU_FEATURE_TYPE_WEBGL,
+                    base::Bind(&RequirementsProvider::IsWebGLAvailable,
+                               weak_factory_.GetWeakPtr()));
+                webgl_checker_->CheckGPUFeatureAvailability();
+              }
+              async_webgl_checks_.push_back(
+                  GPUFeatureRequest(extension->id(), service->AsWeakPtr()));
+            }
+          } else if (feature == "css3d") {
+            if (checked_for_css3d_) {
+              if (!css3d_supported_) {
+                errors->push_back(ASCIIToUTF16(kCSS3dError));
+              }
+            } else {
+              *async = true;
+              // If the check is not ongoing, request one.
+              if (!css3d_checker_.get()) {
+                css3d_checker_ = new GPUFeatureChecker(
+                    content::GPU_FEATURE_TYPE_ACCELERATED_COMPOSITING,
+                    base::Bind(&RequirementsProvider::IsCSS3dAvailable,
+                               weak_factory_.GetWeakPtr()));
+                css3d_checker_->CheckGPUFeatureAvailability();
+              }
+              async_css3d_checks_.push_back(
+                  GPUFeatureRequest(extension->id(), service->AsWeakPtr()));
+            }
+          }
+        }
+      }
+    }
+  }
+  return errors->empty();
+}
+
+void RequirementsProvider::IsWebGLAvailable(bool available) {
+  webgl_supported_ = available;
+  checked_for_webgl_ = true;
+
+  // The original assumption of true is valid.
+  if (webgl_supported_) {
+    async_webgl_checks_.clear();
+    return;
+  }
+
+  // Answer all requests that are pending on the webgl check.
+  GPUFeatureRequest request;
+  while (!async_webgl_checks_.empty()) {
+    request = async_webgl_checks_.front();
+    async_webgl_checks_.pop_front();
+    if (request.weak_service.get()) {
+      request.weak_service->UnsupportedRequirements(
+          request.extension_id, ASCIIToUTF16(kWebGlError),
+          true /* disable the extension */);
+    }
+  }
+}
+
+void RequirementsProvider::IsCSS3dAvailable(bool available) {
+  css3d_supported_ = available;
+  checked_for_css3d_ = true;
+
+  // The original assumption of true is valid.
+  if (css3d_supported_) {
+    async_css3d_checks_.clear();
+    return;
+  }
+
+  // Answer all requests that are pending on the css3d check.
+  GPUFeatureRequest request;
+  while (!async_css3d_checks_.empty()) {
+    request = async_css3d_checks_.front();
+    async_css3d_checks_.pop_front();
+    if (request.weak_service.get()) {
+      request.weak_service->UnsupportedRequirements(
+          request.extension_id, ASCIIToUTF16(kCSS3dError),
+          true /* disable the extension */);
+    }
+  }
+}
+
+RequirementsProvider::GPUFeatureRequest::GPUFeatureRequest()
+    : extension_id(""),
+      weak_service() {
+}
+
+RequirementsProvider::GPUFeatureRequest::GPUFeatureRequest(
+    const std::string& id, base::WeakPtr<ExtensionService> service)
+    : extension_id(id),
+      weak_service(service) {
+}
+
+RequirementsProvider::GPUFeatureRequest::~GPUFeatureRequest() {
+}
+
+}  // namespace extensions