Add deprecation warnings to old powerful features on insecure origins.

Source/core/frame/UseCounter.cpp

Index: Source/core/frame/UseCounter.cpp
diff --git a/Source/core/frame/UseCounter.cpp b/Source/core/frame/UseCounter.cpp
index 7cce5a0ef4b188f6b95262f9673cede6dd469b05..a35b5de48de1d1500a79b8ab3ae48a9b8d5ba0dd 100644
--- a/Source/core/frame/UseCounter.cpp
+++ b/Source/core/frame/UseCounter.cpp
@@ -899,6 +899,22 @@ String UseCounter::deprecationMessage(Feature feature)
     case CSSKeyframesRuleInsertRule:
         return "'CSSKeyframesRule.insertRule()' is deprecated and will be removed in M45, around August 2015. Please use 'CSSKeyframesRule.appendRule()' instead.";
 
+    // Powerful features on insecure origins (https://goo.gl/rStTGz)
+    case GeolocationInsecureOrigin:
+        return "Geolocation via getCurrentPosition() and watchPosition() will be deprecated over insecure origins in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
+
+    case GetUserMediaInsecureOrigin:
+        return "getUserMedia() will be deprecated over insecure origins in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
+
+    case DeviceMotionInsecureOrigin:

[philipj_slow, 2015/05/01 22:36:58]

The DeviceMotionInsecureOrigin and DeviceOrientationInsecureOrigin use counters
are both around 20%, this will amount to console spam which in turn causes
people to take deprecation messages less seriously. Is there a credible plan for
disabling device motion and device orientation on insecure origins? At this
level of usage, there's little chance that deprecation messages will bring usage
down to a level where we would normally consider breaking changes.

[jww, 2015/05/05 21:29:53]

That's a great point, and my mistake for not checking those stats earlier. Those
usage numbers are incredibly high, so I'm suspicious that something funky is
going on (a la some common library automatically registers a 'devicemotion'
event), but until we can figure out what's going on, I'll remove the deprecation
message.

[philipj_slow, 2015/05/06 07:43:55]

Thanks!

+        return "The 'devicemotion' event will be deprecated over insecure origins in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
+
+    case DeviceOrientationInsecureOrigin:
+        return "The 'deviceorientation' event will be deprecated over insecure origins in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
+
+    case FullscreenInsecureOrigin:

[philipj_slow, 2015/05/01 22:36:58]

This ought to be OK, combined usage of all the fullscreen entry points isn't
terribly high:
https://www.chromestatus.com/metrics/feature/timeline/popularity/168
https://www.chromestatus.com/metrics/feature/timeline/popularity/170
https://www.chromestatus.com/metrics/feature/timeline/popularity/176
https://www.chromestatus.com/metrics/feature/timeline/popularity/177

+        return "requestFullscreen() will be deprecated over insecure origins in the future. You should consider switching your application to a secure origin, such as HTTPS. See https://goo.gl/rStTGz for more details.";
+
     // Features that aren't deprecated don't have a deprecation message.
     default:
         return String();