DevTools: sort sourceMap mappings since they might not be ordered.

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 8101ab0fef1540eb16919d787b4440596641d2bf..07c42d63717becd8fee2a615089e9f9b94174b1d 100644
--- a/third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js
+++ b/third_party/WebKit/Source/devtools/front_end/sdk/SourceMap.js
@@ -83,6 +83,17 @@ SDK.SourceMapEntry = class {
     this.sourceColumnNumber = sourceColumnNumber;
     this.name = name;
   }
+
+  /**
+   * @param {!SDK.SourceMapEntry} entry1
+   * @param {!SDK.SourceMapEntry} entry2
+   * @return {number}
+   */
+  static compare(entry1, entry2) {
+    if (entry1.lineNumber !== entry2.lineNumber)
+      return entry1.lineNumber - entry2.lineNumber;
+    return entry1.columnNumber - entry2.columnNumber;
+  }
 };
 
 /**
@@ -481,6 +492,9 @@ SDK.TextSourceMap = class {
       this._mappings.push(new SDK.SourceMapEntry(
           lineNumber, columnNumber, sourceURL, sourceLineNumber, sourceColumnNumber, names[nameIndex]));
     }
+
+    // As per spec, mappings are not necessarily sorted.
+    this._mappings.stableSort(SDK.SourceMapEntry.compare);
   }
 
   /**