Auto merge of #11817 - zmike:master, r=metajack

embedding README updates

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More current directions for running/testing cef.

@jdm @larsbergstrom @metajack literally anyone

---
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- [X ] `./mach build -d` does not report any errors
- [X ] `./mach test-tidy` does not report any errors

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- [ ] There are tests for these changes OR
- [ X] These changes do not require tests because I said so

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ports/cef/README.md

@@ -1,15 +1,11 @@
 How to test:
 
-1. Go to http://cefbuilds.com/ and download a binary for your OS/arch
+1. Build Servo's embedding crate (```./mach build-cef [--release]```)
-2. Unpack the (huge) archive
+2. Build ECEF (https://github.com/zmike/ecef)
-3. Create both Debug and Release build types for CEF (```./build.sh [Debug|Release]```)
+3. See ECEF README
-4. Build servo with ```./mach build-cef [--release]```
+4. Enjoy CEF-powered crashes
-5. Run a CEF-based executable with the embedding crate preloaded:
-	* Linux: ```LD_LIBRARY_PATH=/path/to/cef-bin-unpack-dir/out/$build_type LD_PRELOAD=/path/to/servo/build/libembedding-*.so [CEF EXE]```
-6. Enjoy CEF-powered crashes
 
 Notes:
-* Running with the Debug build in GDB is EXTREMELY slow on startup. Only use this if you are actively debugging an unimplemented CEF interaction.
 * The contents of `interfaces/` are entirely autogenerated. To
   regenerate, see https://github.com/zmike/cef-rebase/blob/master/README.md for full instructions