DevTools: Dont compile large files

Compiling very large files (40mb) will crash DevTools

Bug: 795363
Change-Id: I15108f3cc6b09daa3501782626dee734e3e3f049
Reviewed-on: https://chromium-review.googlesource.com/835416Reviewed-by: Andrey Lushnikov <lushnikov@chromium.org>
Commit-Queue: Joel Einbinder <einbinder@chromium.org>
Cr-Commit-Position: refs/heads/master@{#525221}

third_party/WebKit/Source/devtools/front_end/sources/JavaScriptCompilerPlugin.js

@@ -73,8 +73,11 @@ Sources.JavaScriptCompilerPlugin = class {
     if (!currentExecutionContext)
       return;
 
-    this._compiling = true;
     var code = this._textEditor.text();
+    if (code.length > 1024 * 1024)
+      return;
+
+    this._compiling = true;
     var result = await runtimeModel.compileScript(code, '', false, currentExecutionContext.id);
 
     this._compiling = false;