DevTools: Add Ctrl-A and Ctrl-E shortcuts to CodeMirror

On Mac, Ctrl-A and Ctrl-E go to the start and end of a line respectively.

BUG=648331

Review-Url: https://codereview.chromium.org/2352793002
Cr-Commit-Position: refs/heads/master@{#419610}

third_party/WebKit/Source/devtools/front_end/text_editor/CodeMirrorTextEditor.js

@@ -109,6 +109,8 @@ WebInspector.CodeMirrorTextEditor = function(options)
         "Alt-Right": "goGroupRight",
         "Ctrl-Left": "moveCamelLeft",
         "Ctrl-Right": "moveCamelRight",
+        "Ctrl-A": "goLineLeft",
+        "Ctrl-E": "goLineRight",
         "Shift-Ctrl-Left": "selectCamelLeft",
         "Shift-Ctrl-Right": "selectCamelRight",
         "Cmd-Left": "goLineStartSmart",