Add a --use-angle flag for selecting the ANGLE renderer.

ui/gl/gl_switches.h

Index: ui/gl/gl_switches.h
diff --git a/ui/gl/gl_switches.h b/ui/gl/gl_switches.h
index 0715ad9ae8b71905ab83157f493162277e5f3794..15baa8e745914bd16918284db6aee1288b23276e 100644
--- a/ui/gl/gl_switches.h
+++ b/ui/gl/gl_switches.h
@@ -19,6 +19,13 @@ GL_EXPORT extern const char kGLImplementationEGLName[];
 GL_EXPORT extern const char kGLImplementationSwiftShaderName[];
 extern const char kGLImplementationMockName[];
 
+GL_EXPORT extern const char kANGLEImplementationDefaultName[];
+GL_EXPORT extern const char kANGLEImplementationD3D9Name[];
+GL_EXPORT extern const char kANGLEImplementationD3D11Name[];
+GL_EXPORT extern const char kANGLEImplementationWARPName[];
+GL_EXPORT extern const char kANGLEImplementationOpenGLName[];
+GL_EXPORT extern const char kANGLEImplementationOpenGLESName[];
+
 }  // namespace gfx
 
 namespace switches {
@@ -31,11 +38,11 @@ GL_EXPORT extern const char kGpuNoContextLost[];
 
 GL_EXPORT extern const char kSupportsDualGpus[];
 
+GL_EXPORT extern const char kUseANGLE[];
 GL_EXPORT extern const char kUseGL[];
 GL_EXPORT extern const char kSwiftShaderPath[];
 GL_EXPORT extern const char kTestGLLib[];
 GL_EXPORT extern const char kUseGpuInTests[];
-GL_EXPORT extern const char kUseWarp[];
 GL_EXPORT extern const char kEnableUnsafeES3APIs[];
 
 // These flags are used by the test harness code, not passed in by users.