Add testing for subscription from service workers

third_party/WebKit/Source/modules/push_messaging/PushManager.cpp

Index: third_party/WebKit/Source/modules/push_messaging/PushManager.cpp
diff --git a/third_party/WebKit/Source/modules/push_messaging/PushManager.cpp b/third_party/WebKit/Source/modules/push_messaging/PushManager.cpp
index c6fd24f3058c81833a64378776ae5abfa7f115f3..9cc076a618b9882b06787a438ac22187164be6e7 100644
--- a/third_party/WebKit/Source/modules/push_messaging/PushManager.cpp
+++ b/third_party/WebKit/Source/modules/push_messaging/PushManager.cpp
@@ -38,14 +38,14 @@ String bufferSourceToString(const ArrayBufferOrArrayBufferView& applicationServe
 {
     // Check the validity of the sender info. It must be a 65 byte unencrypted key,
     // which has the byte 0x04 as the first byte as a marker.
-    char* input;
+    unsigned char* input;
     int length;
     if (applicationServerKey.isArrayBuffer()) {
-        input = static_cast<char*>(
+        input = static_cast<unsigned char*>(
             applicationServerKey.getAsArrayBuffer()->data());
         length = applicationServerKey.getAsArrayBuffer()->byteLength();
     } else if (applicationServerKey.isArrayBufferView()) {
-        input = static_cast<char*>(
+        input = static_cast<unsigned char*>(
             applicationServerKey.getAsArrayBufferView()->buffer()->data());
         length = applicationServerKey.getAsArrayBufferView()->buffer()->byteLength();
     } else {
@@ -54,7 +54,7 @@ String bufferSourceToString(const ArrayBufferOrArrayBufferView& applicationServe
     }
 
     if (length == 65 && input[0] == 0x04)
-        return WebString::fromUTF8(input, length);
+        return WebString::fromLatin1(input, length);

[Michael van Ouwerkerk, 2016/03/30 09:50:04]

Or maybe only here. Maybe find a single best place for documenting why this
needs to be latin1 :-)

[harkness, 2016/03/30 10:51:49]

I documented it all three places. Documentation is good.

     exceptionState.throwDOMException(InvalidAccessError, "The provided applicationServerKey is not valid.");
     return String();
 }