Fixes 590477: Style pane numeric property change modifier shortcuts are undiscoverable. Shift mouse…

third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js

Index: third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js b/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
index 9b462083694f1c3a7b0797f5c505f7162305af29..e3a9db1f8dc92713d9631571c6e372f88ab4e240 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js
@@ -301,9 +301,10 @@ WebInspector._valueModificationDirection = function(event)
 {
     var direction = null;
     if (event.type === "mousewheel") {
-        if (event.wheelDeltaY > 0)
+        // When shift is pressed while spinning mousewheel, delta comes as wheelDeltaX.
+        if (event.wheelDeltaY > 0 || event.wheelDeltaX > 0)
             direction = "Up";
-        else if (event.wheelDeltaY < 0)
+        else if (event.wheelDeltaY < 0 || event.wheelDeltaX < 0)
             direction = "Down";
     } else {
         if (event.keyIdentifier === "Up" || event.keyIdentifier === "PageUp")
@@ -363,14 +364,15 @@ WebInspector._modifiedFloatNumber = function(number, event)
     if (!direction)
         return number;
 
-    var arrowKeyOrMouseWheelEvent = (event.keyIdentifier === "Up" || event.keyIdentifier === "Down" || event.type === "mousewheel");
-
-    // Jump by 10 when shift is down or jump by 0.1 when Alt/Option is down.
-    // Also jump by 10 for page up and down, or by 100 if shift is held with a page key.
+    // Precision modifier keys work with both mousewheel and up/down keys.
+    // When ctrl is pressed, increase by 100
+    // When shift is pressed, increase by 10
+    // When alt is pressed, increase by 0.1
+    // Otherwise increase by 1
     var changeAmount = 1;
-    if (event.shiftKey && !arrowKeyOrMouseWheelEvent)
+    if (WebInspector.KeyboardShortcut.eventHasCtrlOrMeta(event))
         changeAmount = 100;
-    else if (event.shiftKey || !arrowKeyOrMouseWheelEvent)
+    else if (event.shiftKey)
         changeAmount = 10;
     else if (event.altKey)
         changeAmount = 0.1;