[inspector] added Debugger.getPossibleBreakpoints method

src/inspector/js_protocol.json

 {
     "version": { "major": "1", "minor": "2" },
     "domains": [
     {
         "domain": "Schema",
         "description": "Provides information about the protocol schema.",
         "types": [
             {
                 "id": "Domain",
                 "type": "object",
@@ skipping 520 matching lines @@
                 "description": "Sets JavaScript breakpoint at a given location."
             },
             {
                 "name": "removeBreakpoint",
                 "parameters": [
                     { "name": "breakpointId", "$ref": "BreakpointId" }
                 ],
                 "description": "Removes JavaScript breakpoint."
             },
             {
+                "name": "getPossibleBreakpoints",
+                "parameters": [
+                    { "name": "start", "$ref": "Location", "description": "Start of range to search possible breakpoint locations in." },
+                    { "name": "end", "$ref": "Location", "optional": true, "description": "End of range to search possible breakpoint locations in (excluding). When not specifed, end of scripts is used as end of range." }
+                ],
+                "returns": [
+                    { "name": "locations", "type": "array", "items": { "$ref": "Location" }, "description": "List of the possible breakpoint locations." }
+                ],
+                "description": "Returns possible locations for breakpoint. scriptId in start and end range locations should be the same.",
+                "experimental": true
+            },
+            {
                 "name": "continueToLocation",
                 "parameters": [
                     { "name": "location", "$ref": "Location", "description": "Location to continue to." }
                 ],
                 "description": "Continues execution until specific location is reached."
             },
             {
                 "name": "stepOver",
                 "description": "Steps over the statement."
             },
@@ skipping 437 matching lines @@
             {
                 "name": "heapStatsUpdate",
                 "description": "If heap objects tracking has been started then backend may send update for one or more fragments",
                 "parameters": [
                     { "name": "statsUpdate", "type": "array", "items": { "type": "integer" }, "description": "An array of triplets. Each triplet describes a fragment. The first integer is the fragment index, the second integer is a total count of objects for the fragment, the third integer is a total size of the objects for the fragment."}
                 ]
             }
         ]
     }]
 }