Don't use a global share group for the passthrough command buffer contexts.

gpu/command_buffer/common/gles2_cmd_utils.cc

Index: gpu/command_buffer/common/gles2_cmd_utils.cc
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.cc b/gpu/command_buffer/common/gles2_cmd_utils.cc
index 6eb9b8e0827283f571e4fe4879ce80b9f9a90feb..129934bfa1f2c0cda1abc35c7165c5ee7dd275d6 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -1878,6 +1878,36 @@ bool IsWebGLContextType(ContextType context_type) {
   return false;
 }
 
+bool IsWebGL1OrES2ContextType(ContextType context_type) {
+  // Switch statement to cause a compile-time error if we miss a case.
+  switch (context_type) {
+    case CONTEXT_TYPE_WEBGL1:
+    case CONTEXT_TYPE_OPENGLES2:
+      return true;
+    case CONTEXT_TYPE_WEBGL2:
+    case CONTEXT_TYPE_OPENGLES3:
+      return false;
+  }
+
+  NOTREACHED();
+  return false;
+}
+
+bool IsWebGL2OrES3ContextType(ContextType context_type) {
+  // Switch statement to cause a compile-time error if we miss a case.
+  switch (context_type) {
+    case CONTEXT_TYPE_OPENGLES3:
+    case CONTEXT_TYPE_WEBGL2:
+      return true;
+    case CONTEXT_TYPE_WEBGL1:
+    case CONTEXT_TYPE_OPENGLES2:
+      return false;
+  }
+
+  NOTREACHED();
+  return false;
+}
+
 ContextCreationAttribHelper::ContextCreationAttribHelper()
     : gpu_preference(gl::PreferIntegratedGpu),
       alpha_size(-1),