Use .packages instead of pubspec.yaml

.travis.yml

 language: dart
 sudo: required
 dist: trusty
 dart:
   - dev
 cache:
   directories:
     - $HOME/.npm
     - $HOME/.nvm
     - $HOME/.pub-cache/hosted
@@ skipping 17 matching lines @@
   - if [ "$CXX" == "clang++" ]; then sudo apt-get install --allow-unauthenticated -qq clang-3.4; fi
   - if [ "$CXX" == "clang++" ]; then export CXX="clang++-3.4"; fi
 
   - if [ "$CXX" ]; then $CXX --version ; fi
 
   # Install Depot Tools
   - git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
   - export PATH=`pwd`/depot_tools:"$PATH"
 
   # Checkout everything if we're building the SDK
-  - 'gclient config --spec=''solutions = [ { "name": ".", "url": "git@github.com:dart-lang/sdk.git", "deps_file": "DEPS", "managed": False, "custom_vars": { "dart_root": "." } } ]'''
-  - if [ "$CXX" ]; then gclient sync ; fi
+  - cd ..
+  - 'gclient config --spec=''solutions = [ { "name": "sdk", "url": "git@github.com:dart-lang/sdk.git", "deps_file": "DEPS", "managed": False } ]'''
+  - gclient sync
+  - cd sdk
 
-  # If a C++ compiler is set, built the SDK - else keep the preinstalled.
+  # If a C++ compiler is set, build the SDK - else use the preinstalled SDK instead.
   - if [ "$CXX" ]; then ./tools/build.py -m release create_sdk ; fi
   - if [ "$CXX" ]; then export PATH=`pwd`/out/ReleaseX64/dart-sdk/bin:"$PATH" ; fi
   - dart --version
 
   # DDC setup
   - cd pkg/dev_compiler
   - pub global activate dart_coveralls
   - export CHROME_CANARY_BIN=`./tool/get_chrome_canary.sh`
   - export DISPLAY=:99.0
   - sh -e /etc/init.d/xvfb start
+install:
+  # Empty to suppress default pub get behavior
 before_script:
   # Node modules used by DDC
   - nvm install 5.5.0
   - npm install
 script:
   # Run DDC tests
   - if [[ -z "$TEST" ]]; then ./tool/presubmit.sh ; fi
   - if [[ "$TEST" == coverage ]]; then ./tool/build_sdk.sh && ./tool/coverage.sh ; fi
   - if [[ "$TEST" == node ]]; then ./tool/node_test.sh ; fi
 env:
   - ANALYZER=master
   - ANALYZER=master DDC_BROWSERS=Firefox
   - ANALYZER=master CXX=g++
   - ANALYZER=master CXX=clang++
   - TEST=coverage
   - TEST=node
 matrix:
   allow_failures:
     - env: TEST=node
     - env: ANALYZER=master DDC_BROWSERS=Firefox
-    - env: ANALYZER=master CXX=clang++
     - env: ANALYZER=master CXX=g++
 notifications:
   email:
     recipients:
       - dev-compiler+buildbot@dartlang.org
     on_failure: change