Revert of DevTools: support resolving a UILocation to multiple raw script locations

third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js

Index: third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js
diff --git a/third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js b/third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js
index 626b08ccbc2180a503ef0301cf26996e011f5c43..6ff41459509fc63009e271a4d5d4c1617c9b7967 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js
@@ -345,15 +345,23 @@
   /**
    * @param {string} sourceURL
    * @param {number} lineNumber
-   * @return {!Array<!SDK.SourceMapEntry>}
-   */
-  mappingsForLine(sourceURL, lineNumber) {
+   * @return {?SDK.SourceMapEntry}
+   */
+  firstSourceLineMapping(sourceURL, lineNumber) {
     var mappings = this._reversedMappings(sourceURL);
-    var startIndex = mappings.lowerBound(lineNumber, (lineNumber, mapping) => lineNumber - mapping.sourceLineNumber);
-    var endIndex = startIndex;
-    while (endIndex < mappings.length && mappings[endIndex].sourceLineNumber === lineNumber)
-      ++endIndex;
-    return mappings.slice(startIndex, endIndex);
+    var index = mappings.lowerBound(lineNumber, lineComparator);
+    if (index >= mappings.length || mappings[index].sourceLineNumber !== lineNumber)
+      return null;
+    return mappings[index];
+
+    /**
+     * @param {number} lineNumber
+     * @param {!SDK.SourceMapEntry} mapping
+     * @return {number}
+     */
+    function lineComparator(lineNumber, mapping) {
+      return lineNumber - mapping.sourceLineNumber;
+    }
   }
 
   /**