Expose WebCrypto's lookupAlgorithmInfo.

public/platform/WebCryptoAlgorithm.h

Index: public/platform/WebCryptoAlgorithm.h
diff --git a/public/platform/WebCryptoAlgorithm.h b/public/platform/WebCryptoAlgorithm.h
index 0a8e9b49c2d67ad6b5008af39e38771e1239afee..253c3265270ab00d8af4a467ea519121abf192f4 100644
--- a/public/platform/WebCryptoAlgorithm.h
+++ b/public/platform/WebCryptoAlgorithm.h
@@ -85,6 +85,19 @@ enum WebCryptoAlgorithmParamsType {
     WebCryptoAlgorithmParamsTypeAesCtrParams,
 };
 
+struct WebCryptoAlgorithmInfo {
+    typedef char ParamsTypeOrUndefined;
+    static const ParamsTypeOrUndefined Undefined = -1;
+
+    // The canonical (case-sensitive) name for the algorithm.
+    const char* name;
+
+    // A map from the operation to the expected parameter type of the algorithm.
+    // If an operation is not applicable for the algorithm, set to Undefined.
+    const ParamsTypeOrUndefined operationToParamsType[WebCryptoOperationLast + 1];
+};
+
+
 class WebCryptoAesCbcParams;
 class WebCryptoAesKeyGenParams;
 class WebCryptoHmacImportParams;
@@ -115,6 +128,16 @@ public:
     BLINK_PLATFORM_EXPORT static WebCryptoAlgorithm createNull();
     BLINK_PLATFORM_EXPORT static WebCryptoAlgorithm adoptParamsAndCreate(WebCryptoAlgorithmId, WebCryptoAlgorithmParams*);
 
+    // Returns a WebCryptoAlgorithmInfo for the algorithm with the given ID. If
+    // the ID is invalid, return 0. The caller can assume the pointer will be
+    // valid for the program's entire runtime.
+    BLINK_PLATFORM_EXPORT static const WebCryptoAlgorithmInfo* lookupAlgorithmInfo(WebCryptoAlgorithmId);
+
+    // Returns the canonical (case-sensitive) name for the algorithm with the
+    // given ID as a null-terminated C-string literal. Caller can assume the
+    // pointer will be valid for the program's entire runtime.
+    BLINK_PLATFORM_EXPORT static const char* idToName(WebCryptoAlgorithmId);
+
     ~WebCryptoAlgorithm() { reset(); }
 
     WebCryptoAlgorithm(const WebCryptoAlgorithm& other) { assign(other); }