Add GN build

Change-Id: Ibb0c352d3b8d6a9a0b9d468e51cac286e6863788

.github/workflows/cmake.yml

@@ -1,3 +1,4 @@
+# Workflow to build Dawn using CMake
 name: CMake
 
 on:

.github/workflows/gn.yml

@@ -0,0 +1,54 @@
+# Workflow to build Dawn using GN
+name: GN
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      # Set fail-fast to false to ensure that feedback is delivered for all matrix combinations. Consider changing this to true when your workflow is stable.
+      fail-fast: false
+
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        is_debug: [true, false]
+        is_component_build: [true, false]
+        is_clang: [true, false]
+
+        exclude:
+          - os: macos-latest
+            is_clang: false
+
+    steps:
+    - name: Install Ubuntu build dependencies
+      if: matrix.os == 'ubuntu-latest'
+      run: |
+        sudo apt update
+        sudo apt install libgl-dev libx11-xcb-dev libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev libxext-dev wayland-protocols libwayland-dev libxkbcommon-dev
+
+    - name: Install Depot Tools
+      uses: newkdev/[email protected]
+
+    - uses: actions/checkout@v3
+
+    - name: gclient sync
+      run: gclient sync
+
+    - name: Set up sccache
+      uses: mozilla-actions/[email protected]
+
+    - name: Generate build files
+      run: gn gen out/build --args=cc_wrapper=sccache is_debug=${{ matrix.is_debug }} is_component_build=${{ matrix.is_component_build }} is_clang=${{ matrix.is_clang }}
+      env:
+        SCCACHE_GHA_ENABLED: "true"
+
+    - name: Build
+      run: autoninja -C out/build
+      env:
+        SCCACHE_GHA_ENABLED: "true"